Chapter 11 Observing Air Power at Work in Sector Sarajevo, 1993– 1994: A Personal Account

Observing Air Power at Work in Sector Sarajevo, 1993– 1994:
A Personal Account

F. Roy Thomas

Originally published as Chapter 11 in Air Power in UN Operations: Wings for Peace (A. Walter Dorn, Ed.), Ashgate Publishing, Farnham, UK 2014, pp. 193-211. (pdf version)


No one watched the weather more closely in the fall of 1993 than the unarmed United Nations Military Observers (UNMOs) who manned the observation posts surrounding besieged Sarajevo, capital of the new state of Bosnia-Herzegovina. Every UNMO who was hoping to take a well-deserved time off from monitoring the shelling and counting the dead had to leave via the international community’s air bridge to Ancona, Italy, or the UN charter flights to Zagreb, Croatia.[1] Every UNMO about to be posted out to a more benign sector had to leave through local airports. Truly The Road to Sarajevo that Major-General Lewis Mackenzie followed could not be taken by the 30 UNMOs who rotated into or out of Sector Sarajevo each month.[2] The life of every military observer in Sector Sarajevo was shaped to some extent by at least one of the tools of air power: they all arrived by air! Indeed, this chapter is literally made possible by air power, as it outlines how aerospace tools shaped what UNMOs in Sarajevo did from 15 October 1993 through 17 July 1994. Fifteen minutes before landing on my first flight into the besieged city, the day that I arrived to assume command of the UNMOs of Sector Sarajevo, I put on my flak jacket and helmet. My UNMOs in Sector Sarajevo, serving as part of the much larger United Nations Protection Force (UNPROFOR), were dispersed among teams in observation posts: some inside the Bosnian city, some surrounding the Bosnian capital; a team in the so-called safe-haven in the city of Goražde, the only UNPROFOR presence there; and a team in the town of Žepa, also home to a Ukrainian UNPROFOR mechanized infantry company. The two safe-haven teams in Goražde and Žepa, in eastern Bosnia on the banks of the Drina, communicated with me in Sarajevo using capsat, a form of texting using satellite communications. “UNMO Sarajevo”, as it was designated, included from 120 to 200 officers from any of 39 countries from all continents as well as up to 50 locals hired as UN interpreters.[3] “Welcome to Hell” said the graffiti smeared on the wall of a building. “Welcome”, indeed, to what detail can be shared about how air power shaped UN observer teams during my nine months as the Senior UN Military Observer (SMO) for Sector Sarajevo.[4]

Situational Awareness October 1993

            There are no good guys, only villains and victims.

                                                                                                    Richard Round, 1993[5]

Attempting to label the conflicts ongoing in the former Yugoslavia was, and remains, a challenge. Canadian Colonel George Oehring suggests these labels:[6]

  • in Slovenia, June to July 1991: “the War of Slovenian Independence”;
  • in what is now Croatia, from July 1991 to August 1995: “the War of Croatian Partition”;
  • in current Bosnia-Herzegovina, from April 1992 to December 1995: “the War of Bosnian Serb Secession”;
  • related to the above, alongside in 1993–1994: “the Bosnian Croat–Bosnian Muslim War”;
  • April 1993 to August 1995: “the War of the BihaćPocket”, which occurred within the above-mentioned “War of Bosnian Serb Secession”.

related to the above, alongside in 1993–1994: “the Bosnian Croat–Bosnian Muslim War”;
April 1993 to August 1995: “the War of the BihaćPocket”, which occurred within the above-mentioned “War of Bosnian Serb Secession”.

In the case of the last three “wars” two of the three belligerent parties, the Bosnian Serbs and the Bosnian Croats, had no international standing as political entities. In UNPROFOR’s Bosnia-Herzegovina Command (BHC), the legitimate government (of Bosnia-Herzegovina) came to be associated with “Muslims” but, in fact, included both Bosnian Serbs and Bosnian Croats. Certainly 1993–1994 Sarajevo could be considered a war zone in all but name, at least in terms of the volume of fire and subsequent casualties.[7] For military personnel serving with UNPROFOR, including UNMOs, there was no identifiable enemy to be fitted in the templates used in Cold War planning: there were only enemies of the peace!

In Sarajevo itself the complexity of the political and military situation was further illustrated by the fact that a Croatian brigade had responsibility for holding part of the defensive perimeter against Bosnian Serbs in UNPROFOR. Yet only 30 km away in Kiseljak, Croatians were allied with Bosnian Serbs against Bosnian government forces and were even suspected of “lobbing” the odd shell into Sarajevo, on occasion even hitting their own forces. On many pre-war ethnic maps Sarajevo was shown as “white”, that is, with no ethnic colour assigned. In 1993, in and around Sarajevo, as elsewhere, all sides were trying to paint the map with their own particular ethnic colour.

The response of the international community to the conflict was equally complex. For example, Canadian military personnel served not only in several UN military deployments to the region but also under the auspices of the European Community, the Organization for Security and Cooperation in Europe and the Western European Union. Canadians also flew North Atlantic Treaty Organization (NATO) assets deployed in support of the United Nations, giving rise to disputes about whether those Canadians were entitled, under the regulations, to receive the Canadian peacekeeping medal.

UNMO Sarajevo was one of the organizations used by the international community to tackle the Bosnian conflict. The four battalions of UNPROFOR in the Sarajevo environs, under command of French Brigadier General André Soubirou, constituted another Sector Sarajevo military component who reported, as did I, to the Lieutenant General commanding BHC.

The Office of the United Nations High Commissioner for Refugees (UNHCR) was the lead non-military agency, responsible ultimately to UN Headquarters, while a host of other non-governmental organizations were also present, including the powerful Doctors without Borders and the International Committee of the Red Cross. UNMOs in Sector Sarajevo provided the only permanent uniformed UN presence, albeit unarmed, on Bosnian Serb territory around Sarajevo. UNMO reports were sent up a separate channel direct to the observer mission headquarters in Zagreb and often were copied, for example in daily Situation Reports, direct to UN Headquarters in New York. The role of the more than one thousand UNMOs in UNPROFOR, like the naval and air resources supporting the many UN Security Council resolutions, is often overlooked.

The principal media focus of the international community in October 1993 seemed to be on Sarajevo and its siege. Therefore it is appropriate to narrow the discussion of the use of air power in so-called peace support operations during this period to this specific case, which was so well publicized by media, pundits and practitioners at the time, perhaps because pre-war multiethnic Sarajevo, host of the 1984 Winter Olympics, was a model many in the international community hoped would survive as an example for the rest of the fledgling state.

The air-power tools to be discussed in relation to UNMO Sarajevo October 1993 to July 1994 cover the spectrum ranging from aerospace surveillance, combat aircraft, military airlift and charter airlift to contingent aviation in the casualty evacuation role. The impact of these air-power tools on UNMOs will be considered in relation to the ongoing phases of the siege of Sarajevo during this period. On my assuming command in October through to December 1993 there was a continued use of “terror tactics” by all belligerents. Then in January 1994 there appeared to be an attempt to obtain international intervention, culminating with the Market massacre, which killed 68 outright and wounded hundreds. The Market massacre resulted in the February 1994 Sarajevo ceasefire and the creation of a heavy weapons exclusion zone around Sarajevo. Still within Sector Sarajevo’s responsibility but in eastern Bosnia, the situation around safe-haven Goražde deteriorated to the point of an outright Bosnian Serb assault on this large enclave, which eventually ended with another ceasefire and a Goražde exclusion zone. In the meantime the situation around Sarajevo escalated as belligerents increasingly resorted to sniper fire to terrorize and counter opponents’ trenching efforts. Air power played a major part in shaping what happened in most of these phases of the Sarajevo saga, as well as directly impacting on the tasks that the unarmed UNMOs carried out.

Terror Tactics, Sarajevo UN Military Observers and the Tools of Air Power
Failure to Inform

From the time the first shot was fired in the first of these wars in the former Yugoslavia there was ongoing aerospace surveillance to collect data that could have served as valuable intelligence to those on the ground, including the unarmed military observers. Such sharing did not occur, however. Indeed, not only did faulty intelligence in February 1992 lead to the ill-advised attempt to locate the headquarters of UNPROFOR in Sarajevo but also aerospace surveillance data was apparently not made available to support the epic march of Canada’s Royal 22nd Regiment Battlegroup to Sarajevo in June/July 1992; and this failure to share information available from aerospace assets continued during my first few months of command in Fall 1993.[8]

In December 1993 during the use of terror tactics, as commander of UNMO Sarajevo I personally participated in an investigation of an alleged attack by a Bosnian “fighting” patrol on a Serb village near the Bosnian Serb Army Headquarters at Hans Pijesak, in eastern Bosnia but still within Sector Sarajevo’s area of responsibility. I went myself, as SMO, because the Bosnian Serbs rarely asked the United Nations to investigate. Unarmed UNMOs and UNPROFOR troops escorting humanitarian convoys were the only uniformed UN presence in the Bosnian Serb-held areas and were subjected to extensive limitation-of-movement restrictions. I found that there had definitely been a massacre and, in my judgement, it was highly unlikely that the Bosnian Serbs had fabricated this incident. Rather, it seemed to me and my colleague that a guerrilla-type force had infiltrated through the lines and inflicted this atrocity to pass the message that the Bosnian Serbs, being short of manpower, could not protect isolated hamlets, not even one as close as this particular village was to their main military Bosnian headquarters. Exploiting the “old boy network”, I did discover that indeed NATO aerospace assets indicated a pattern of as many as 20 possible destroyed villages.[9] Personally, I believe that information on the map of Serb gun positions that I saw for the first time, years later, at The Hague during the International Criminal Tribunal for the former Yugoslavia, should have been made available to me at my first briefing on assuming command in Sarajevo in October 1993, as it was available from aerial assets controlled by the same NATO nations contributing to UNPROFOR!

UNMOs had to patrol on the Bosnian Serb side to obtain information, at risk from mines, booby traps and belligerent fire often deliberately aimed at them. Yet the information in the target lists provided as a result of aerospace surveillance, which formed the basis of so many UNMO patrols after the February 1994 Sarajevo ceasefire, could have formed the basis of patrol plans during the period of terror tactics (October 1993 to December 1993). On the other hand, intelligence needed to monitor and enforce the No-fly zone (NFZ) through this period was available to NATO air-power assets, compelling compliance in Bosnian airspace, but not to UNMOs on the ground in Bosnia below.

Use of Combat Aircraft

During the terror tactics period, the major impact of combat aircraft, all controlled by NATO under the auspices of Operation Deny Flight, was the enforcement of the NFZ over Bosnian airspace. During my nine months in Sarajevo I only heard a suspected An-2 aircraft flying late at night, but never saw a belligerent aircraft of any type.[10]

Figure 11.1 Layout of UN Military Observer Sarajevo observation posts before ceasefire (A, on 6 February 1994) and after (B, at peak on 24 February 1994).
Source: The author and the International Criminal Tribunal for the former Yugoslavia.

NATO air forces began monitoring the ban on military flights in Bosnian airspace, including Sarajevo, in October 1992 with NATO Airborne Early Warning and Control Force

(NAEW&CF) assets under UN Security Council Resolution (SCR) 781. This was expanded by SCR 816 in March 1993 to include all flights not authorized by UNPROFOR with the addition of provisions for use of NATO combat aircraft to enforce compliance. The time-consuming “Blue Sword” approval process that was later used for combat aircraft in close air support and air strikes was not a factor in enforcement of the NFZ. (“Blue Sword” is the name of the dual-key – UN and NATO – release system for air strikes in Bosnia. Both UN and NATO officials had to authorize strikes. It was a process which caused significant tension and problems.) Moreover, the NAEW&CF assets were in-place to detect fixed-wing violations and, to a lesser extent, helicopter violations.[11] The violators could be shot down immediately. Probably as a result of belligerent capabilities, the NFZ, by 1993, was directed primarily at one belligerent, the Serbs, in the case of Sector Sarajevo.[12]

During this period, October 1993 through January 1994, belligerent terror tactics meant that observation posts around Sarajevo were placed to detect the firing of artillery, mortars, and tanks, or to evaluate the results of such shelling (see Figure 11.1A). The UNMOs also had an established procedure not only to observe the fall of shot but also to investigate the subsequent casualties. The NFZ meant that UNMOs were not watching for terror tactics involving the use of aircraft. The NFZ also meant that the air bridge could operate without the threat of hostile air action while supplying Sarajevo and the Sector Sarajevo safe havens of Žepa and Goražde (airdrops needed in the winter), the rotation of UNPROFOR personnel, including UNMOs, and equipment, and casualty evacuations. However, ground fire remained a concern.

The UN Protection Force, Air Transport, and UN Military Observers

All UNMOs arrived in Sector Sarajevo via UN chartered aircraft from Zagreb to Sarajevo. Normally up to one-quarter of the military observers rotated into or from Sarajevo each month. En route 15 minutes before arrival at Sarajevo airport, passengers including UNMOs would be told to put on their flak jackets and helmets to protect against small arms fire. On arrival all passengers were required to carry all their own baggage.[13] No airport ground personnel, whether civilian or UNPROFOR, would risk carrying someone else’s belongings. Indeed, during my tenure of command, a French officer marshalling passengers for the rush to the terminal was shot by a sniper while several new UNMOs joining my team were disembarking.

Figure 11.2 Hercules aircraft on the tarmac at the airfield in Ancona, Italy.
Source: Photograph by Roy Thomas on one of his four flights from Sarajevo to Ancona on leave.

The International Air Bridge and UN Military Officers

The Sarajevo Airlift commenced 2 July 1992 and ended on 9 January 1996 after delivering 160,536 tons of supplies in 12,895 sorties – see Figure 11.2 for a photograph taken by the author. Ad hoc arrangements brought together military airlift from 21 participating nations.[14] Without this airlift it would have been unlikely that the population of Sarajevo and their political leadership would have withstood the siege. If Sarajevo had fallen there would be no reason for UNMOs being there!

UNHCR controlled the passenger list, impacting on the UNMOs. For example, a Bosnian Serb interpreter working for the UNMOs required a medical operation which he did not trust to have done in Sarajevo or Zagreb and which was not possible in Belgrade due to the embargo. While the individual travelled via the air bridge to Ancona for his initial treatment at an Italian hospital, he was denied access for the necessary medical follow-ups. UN authorities would not change their position, so UNMOs eventually flew this interpreter, who had been awarded an UNPROFOR force commanders’ commendation for bravery in assisting observers, at their own expense, to Ancona commercially.[15]


In addition to participation in the Sarajevo air bridge, the United States Air Force flew 2,200 airdrop sorties to augment delivery of humanitarian aid across Bosnia.[16] In Sector Sarajevo the two safe havens of Žepa and Goražde both received supplies through airdrops, primarily in the winter. In both enclaves the UNMO teams deployed UNMOs to monitor the collection process on the Drop Zone.[17] The chaos on the drop zone in Žepa led to the collaboration between my UNMOs and local leaders, as opposed to a Bosnian military element, in an attempt to form a police force to bring law and order not only to the Žepa drop zone but also to the enclave community itself, which had not accepted the presence of more than 8,000 refugees very willingly. In Goražde, the drop zone was under the tight control of the Bosnian forces that were permitted in Goražde but not “officially” in Žepa, so the UNMO task was to ensure that only humanitarian aid was being received. A separate UNMO team, not from Sarajevo, verified contents when airdrop pallets were loaded in Frankfurt, Germany.

Medical Flights

During this period of terror tactics the threat from ground fire remained. Although fortunately no UNMO required evacuation from Sector Sarajevo during my command, an attempt to have a seriously sick child flown by a French UNPROFOR helicopter from Goražde to Sarajevo failed to take place due to lack of assurance that the air defence assets of belligerents would be not be activated. (Later in April 1994 these Goražde air defence assets did shoot down a NATO fighter.) In this particular case, UNMO military observers from the team in Goražde ended up driving the sick child and mother to Sarajevo.

Without the NFZ these airdrops and medical evacuations would have been risky because such sorties were very vulnerable to hostile air action. A ground fire threat to aircraft of the air bridge and the UNPROFOR charters remained, as landings and take-offs at Sarajevo airport involved a vulnerable flight profile over disputed urban terrain.

January 1994 Brings Additional Tasks

A series of tragic events in January 1994 leading up to the Market Massacre of 5 February suggests that outside intervention was being sought by many in the Sarajevo region. On 3 January 1994, shelling killed 15. On 22 January, shells killed six children who were sledding. On 4 February, ten were killed by shells while waiting in a bread line. At the same time, the shooting at the aircraft on the air bridges connecting the city to the outside world seemed to be almost ignored by the international media. All of these actions, culminating with the 5 February killing of 68 and wounding of over 200 when a single 120 mm mortar round hit Markdale market, did result in outside intervention and a temporary Sarajevo ceasefire. There is an argument based on these events that a party or parties (from one or both sides) sought foreign action to halt the war, at least in the Sarajevo area. During this time of increased military activity, the UNMOs were extremely occupied with observing not only the conduct of the belligerents but also the small arms threat to the ongoing airlift; and the UN charter flights forced further tasks on the observer organization.

One of the observation posts/team sites (L2) provided an overview of the normal approach to Sarajevo airport – see Figure 11.1A. Observation Post L2 is the furthest left triangle. The first step was to monitor transport aircraft in their final approach. National flying regulations dictated different profiles. Additional eyes were added to this team just to observe flights. Based on evidence on where aircraft were hit, the major threat appeared to be small arms fire. This analysis led to other additional tasks for Sarajevo’s military observers. An UNMO Listening and Observation Post was established 500 m from the end of the primary runway, where it was estimated that the transport aircraft were most vulnerable to ground fire. Further, two UNMOs were located in the control tower during the flights (all of which occurred during daylight hours, wind conditions permitting). It was hoped that the new observation post and the UNMOs in the tower could quickly direct UNMO patrols to the suspected location of any small arms fire directed at an incoming or outgoing aircraft. Liaisons between UNMOs and the Bosnian Serb Ilidza brigade located in the primary approach path were also instituted twice a day, specifically to discuss this small arms threat. This particular Bosnian Serb formation provided extensive assistance in deterring small arms fire. Aircraft flying over the disputed Stup suburb of Sarajevo near the airport, a much fought-over area of destroyed and damaged houses, faced a threat from small arms fire from all belligerents. During January there was constant shelling and small arms fire in the Stup area. Determining which side fired from different piles of rubble was difficult. Often aircrews were unaware that they had been hit until they landed.[18] When in January 1994 there was a possibility that the airflow would be interrupted by further small arms fire, the alternative, landbased routes and the need for vehicles created significant challenges for the UNMOs in Sarajevo at a time when some belligerent parties were increasing the casualty count in the hope of foreign intervention.[19] However, even during the height of the aircraft-shooting terror tactics campaigns, only a handful of UNMOs were deployed to Sarajevo by any means other than the UN charter aircraft.

The additional UNMO task of monitoring the flight path to Sarajevo airport further illustrates that the intelligence garnered by international (UN/NATO) aerospace tools was not being shared with UNMOs or, indeed, passed to UNPROFOR contingents on the ground. Yet ironically, the author was asked to help a national intelligence agency collect information on air defence assets.[20] This lack of access to NATO intelligence would change with the implementation of the Sarajevo ceasefire set in place by General Sir Michael Rose, who levered the outrage of the international community into strong pressure on the belligerents to cease firing and then to implement his Sarajevo peace plan.

Air Power in the Implementation of the February 1994 Sarajevo Ceasefire

Two additional air power tools changed completely what UNMOs did around the besieged city with the implementation of General Rose’s Sarajevo peace plan. First, combat air power was used to coerce compliance with a Total Exclusion Zone (TEZ), prohibiting heavy weapons within 20 km of Sarajevo. Secondly, and much more significantly, NATO aerospace surveillance assets were used to provide information as to what heavy weapons had not been moved to the UN-secured heavy weapons collection points.

Now UNMOs had access to a flood of NATO intelligence from aerospace surveillance on a daily basis. In conjunction with French and British contingent reconnaissance assets, a new demanding task for UNMOs was to investigate on the ground why a particular belligerent heavy weapon that was in violation of the TEZ, as identified by NATO aerospace assets, should not be bombed.

Combat Power in a Coercive Role

The mandate to use combat power in close air support of UNPROFOR troops was provided by UN Security Council Resolution 836, 4 June 1993, which provided the coercive threat to influence the belligerents in moving their heavy weapons to the designated UN-controlled weapons collection points. The NATO North Atlantic Council meeting of 9 February 1994 authorized the Commander-in-Chief of NATO’s Southern European forces (CINCSOUTH) to launch air strikes in reply to artillery or mortar attacks on Sarajevo, or against heavy weapons still in the TEZ that had not been placed under the control of the United Nations.[21] The threat of the first potential mission, an air strike to punish shelling, added weight to a ceasefire that the UN Commander was fashioning on that same date between the two belligerents in Sarajevo. The threat of the second potential mission, an air strike to destroy heavy weapons not under UN control, required belligerents to move their heavy weapons to weapons collection points or permit access to UN observers to validate why such heavy weapons could not be moved or were not functioning.

The belligerents in the Sarajevo TEZ were given 10 days, with one extra day of grace, until 21 February, to place all tanks, artillery, mortars, multiple rocket launchers, anti-aircraft missiles, and anti-aircraft guns within 20 km of the centre of Sarajevo, under UN control.[22]

The process of identifying weapons and either monitoring their collection or confirming that the weapons system was inoperable was only one of four parts to the February 1994 ceasefire and peace plan for Sarajevo. Monitoring and maintaining the ceasefire was perhaps more important because no party would permit weapons to be collected if hostilities were imminent and UNMOs were a major element investigating violations. The United Nations also had to quickly position troops between the belligerents, where possible. UNMOs surveyed the confrontation line as part of this process. Finally efforts were being made to create a joint commission to address the issues arising from the Sarajevo ceasefire.[23] The NATO assistance in finding heavy weapons violations was essential, as even if full freedom of movement was given by belligerents, ground reconnaissance resources to do this were limited.

Up until 9 February 1994, only UNMOs and UN troops involved in escort of humanitarian assistance had had any freedom of movement on the Bosnian Serb side. This meant initially that military observers had to work at the front lines to maintain a UN presence, investigate violations on the Serb side, and also start the process of searching for heavy weapons. UNMOs even had to monitor at least one weapons collection point because of its isolation.

By 19 February, the process had developed to the point where NATO was preparing a target list of possible TEZ violations based on aerial surveillance. This NATO list was then passed to UNPROFOR and UNMO Sarajevo, which tasked military observers to proceed to these sites within 24 hours to verify the status of the reported violation.[24] Additional military observers were deployed from other UN sectors to Sarajevo to assist in this and other military observer tasks. General Rose, as part of his Sarajevo peace plan, also deployed special teams of what came to be called Joint Commission Officers (JCOs) to help in this role. The JCO teams reported directly to General Rose, and their communications and prior training permitted the use of these teams to call in air strikes if required.[25]

The difficulties of measuring success in peace support operations become apparent when considering the 21 February deadline set by the TEZ conditions. Shelling had stopped, but was only to be replaced by an increase in sniper fire. Some 237 so-called heavy weapons had by that time been collected in 11 sites on the Bosnia Serb side, and 10 sites ostensibly under control of UNPROFOR troops, with 1 site only monitored by the unarmed military observers. On the Bosnian government side, 47 heavy weapons had been collected at Tito Barracks in Sarajevo itself, also the home of the Ukrainian UN battalion. The NATO/UN threat to bomb translated into partial compliance on the ground.[26] The discovery of 15 armoured personnel carriers and several tanks hidden in a Sarajevo tunnel under Bosnian government control was yet to come, as were many other surprises following the deadline. As late as May, there were still 41 identified heavy weapons that were not under UN control.[27] Thus the process of identifying heavy weapons violations, monitoring them if they were not moved, and controlling weapons that had been collected did not end on 21 February, but continued.[28] There were legitimate explanations for many of the heavy weapons that remained uncollected in the TEZ after the NATO deadline: many could not be moved, either for technical reasons such as no engines in tanks, or because, in the case of some towed guns, the snow or mud prevented grouping until late spring.

Procedural difficulties were also a factor. For example, the exact centre for determining the 20-km radius for the TEZ was not at first specified. It became important, as the Bosnian Serbs had guns near Visoko, close to the edge of the TEZ, but facing away from Sarajevo into Central Bosnia where hostilities continued as the Croats there allied themselves with the Bosnian government. Another procedural issue was the definition of what constituted a heavy weapon. These technical issues demonstrate that simply having the air power to coerce is not enough on its own. UNMOs, because they lived in the communities with interpreters as part of the team, were in a position to undertake not only investigation but also the liaison necessary to bring to light these procedural and technical issues at the local level and seek resolution. Some difficulties, were political, however, and could not be resolved by BHC or even NATO Allied Forces Southern Europe.

In view of the well-known exemptions to NATO enforcement it is difficult to assess what role the NATO air threat actually played in compelling the belligerents to place their heavy weapons in collection points. What is clear is that the use of combat air power to force belligerents to put heavy weapons in designated collection points required UNMOs to validate targets identified by NATO, information which had never been shared before General Rose’s Sarajevo ceasefire.

It should be noted that only on rare occasions was this UNMO task assisted by the limited use of helicopters for UNMO missions, when the snow blocked access to some target sites. In contrast, in Macedonia, where the author served for three months prior to becoming SMO in Sarajevo, his position was allocated a helicopter for monitoring tasks once a week.

The NATO combat aircraft used to enforce compliance with the NFZ ensured that the air assets of the Bosnian Serbs were not utilized to replace ground assets in the Sarajevo siege after the creation of the Sarajevo TEZ. While no belligerent air assets violated the NFZ over Sarajevo, NFZ violations were attempted elsewhere in Bosnia – near Banja Luka for example – in an incident in which four Bosnian Serb aircraft were shot down by NATO.[29]

Air Bridge/Airdrops and UN Air Transport

Restrictions on UNMO land movements by all belligerents continued into the Sarajevo ceasefire. Close air support on checkpoints hindering or limiting freedom of movement were not apparently considered.[30] Therefore the air bridge remained vital to Sarajevo’s continued resupply. Airdrops also continued as weather and Bosnian Serb restrictions on movement continued to hamper surface resupply of Žepa and Goražde. The TEZ and some easing of limits on movement were only taking place in the Sarajevo area.

The United Nations continued to utilize air transport for rotations as well. The Sarajevo ceasefire was used to establish another observation post in hitherto restricted territory to better monitor the Sarajevo runway approaches. During the ceasefire the author was on a Yak-40[31] that was hit by at least 11 small arms bullets on take-off from Sarajevo airport when it was forced to fly over the disputed Stup suburb because of one faulty engine. This aircraft had not been left at Sarajevo for repairs because of a fear of further damage due to mortar fire during the hours of darkness.

Medical Flights

The TEZ applied to a 20-km circle around the Sarajevo area. This restricted the use of French contingent helicopters for medical airlift from the Sector Sarajevo safe havens on the Drina River in Žepa and Goražde. One helicopter medical evacuation of civilians from the safe haven of Žepa in March 1994 illustrates the involvement of not just UNMOs but even high-ranking UNPROFOR officers. The Bosnian Serbs would not give assurances that the French helicopters would not be fired upon in approach to that safe haven. General Soubirou, the UN Sarajevo Sector Commander, told the Serbs that he would be in the first helicopter, clearances or not! He was! However, problems did not end with the arrival of French helicopters in Žepa. This is when the UNMOs become involved. The UNHCR representative and an “outside” doctor were NOT present. When it appeared that the Žepa Pocket’s only dentist – the wife of the local doctor, who was now deciding who was so seriously ill as to merit evacuation – was among those to be flown out, the UNMO team leader in Žepa had to order that she be taken off the passenger list and a valid medical evacuee be substituted.[32]

The Goražde Assault

Goražde fell within the purview of UN Sector Sarajevo headquarters, although only the SMO had military personnel in the form of a team in this large enclave.

The rationale that prompted the selection of Goražde for a Bosnian Serb attack may never be known. What was clear was that a major attack on Goražde was taking place and by 10 April it appeared that the Bosnian Serbs had secured the ground necessary to dominate the city of Goražde itself. The assessment of the Bosnian government situation in Goražde on that date by one military observer was that it was “untenable”.[33]

To stop a total victory by the Bosnian Serbs in their Goražde assault a warning was given by the BHC Deputy Commander, in writing, to the Bosnian Serb political leader, Radovan Karadžić and military commander Ratko Mladić in the afternoon of 10 April 1994, threatening air strikes if the Bosnian Serb attacks continued. Attacks continued. A telephone warning was then made. When these two warnings had no apparent impact, approval was sought and received for NATO aircraft to attack Bosnian Serb tanks and artillery. Two NATO air strikes were made.[34] Serb shelling ceased on 10 April, then resumed on 11 April. NATO aircraft made several passes, with pauses to permit UN warnings to be relayed and subsequent reflection on the part of the Bosnian Serbs to take place, before a Bosnian Serb tank was attacked. In the meantime, on 11 April, the Bosnian Serbs detained the bulk of the UN military personnel on their side of the front line as hostages. This included all the unarmed UNMOs in Sector Sarajevo deployed on the Bosnian Serb side of the confrontation line, including one UNMO en route from the Žepa team to Sarajevo to take compassionate leave.[35] Ominously, in some instances, UN military observers were moved from their accommodations to various Bosnian Serb headquarters, a forecast of the human shield technique that would be exposed to the world in 1995 when NATO launched another series of air strikes. Hostages were only released when a settlement was reached in Goražde.

In Sector Sarajevo this hostage-taking immediately impacted on UNMO operations. Several important negotiations were stopped, for example one attempting to place UNMOs permanently on a Bosnian Serb position in the area of the “sharp stone” feature, which was a favourite sniper firing position for shooting into Sarajevo.[36]

In Goražde proper, it appeared that the Bosnian Serbs were progressing in accordance with their own timetable, unaffected by any threat of NATO air strikes or UN negotiations. On 16 April, resumption of the air strikes resulted in a British Harrier being shot down. This was the last air strike near Goražde and it, too, had not stopped the Bosnian Serb advances. On 19 April 1994, a temporary arrangement for the town of Goražde was agreed to by Bosnian Serbs and UNPROFOR.[37] That same day, UNMOs on the Bosnian Serb side near Sarajevo were given freedom of movement. On 21 April 1994 a 3-km TEZ was created around Goražde.[38] The following day, somewhat after the fact, NATO authorized CINCSOUTH to conduct air strikes against Bosnian Serb heavy weapons and other military targets within a 20-km radius of the centre of Goražde.[39]

The ceasefire and creation of a TEZ around Goražde necessitated an augmentation force of UNMOs collected from the observers presently employed around Sarajevo proper and then deployed to that safe haven. The augmented UNMO Goražde team carried out validation of target tasks in the Goražde TEZ similar to those undertaken around the Sarajevo TEZ. The Goražde ceasefire also resulted in the deployment of two armed UNPROFOR battalions in that safe haven.

Medical Evacuation from Goražde

Bad weather prevented use of air power for several days after the 11 April NATO air strikes but did not stop evacuation of a seriously wounded JCO by helicopter on that day. Finally, on 18 April, the JCOs, who had acted as the Forward Air Controller in Goražde, were evacuated by helicopter at the same time as a medical evacuation of the most critically injured civilians took place.

Air Power and UNMOs During the Increase in Sniping

Although UNMO Sarajevo tasks continued to be strongly shaped by the need to validate ongoing NATO targeting and the monitoring of TEZ violations, the observers increasingly became involved in attempting to deter sniping as hostilities along the confrontation line around the city increased.[40] The presence of observers deterred sniper activity if the first shooter could be identified. UNMO activities again swung back to observe arms fire, with small UNMO teams in the belligerent trenches, especially at night.[41] Coercion by air power was not an effective option in dealing with this belligerent sniping in urban terrain. UNMOs also continued to be tasked to monitor the flight paths used by airlift aircraft.


The tools of air power were seen by me to have truly shaped the tasks that were undertaken by the unarmed UNMOs in Sector Sarajevo. The use of combat aircraft to create compliance with the NFZ in Bosnian airspace meant that the air forces of the neighbouring states of Croatia and Serbia, as well as the fixed wing assets of the Bosnian Serbs, were never observed as a factor in the siege of Sarajevo or operations against the two safe havens in Sector Sarajevo during my nine months as SMO.

From October to December 1993, the NFZ ensured that UNMOs only observed and investigated tank, artillery, mortar, and small-arms fire, never air attacks. The need to counter small-arms threats to transport aircraft shaped the tasks of some UNMOs. UNMO resources had to be dedicated to monitoring the Sarajevo airport flight paths, a task that continued even after the February Sarajevo ceasefire. However, that same ceasefire did bring about the further shaping of UNMO Sarajevo tasks by the tools of air power.

The threat of NATO air strikes against first use of heavy weapons fire made possible the ceasefire and hence a survey of the confrontation line by UNMO teams. More pronounced “shaping” of UNMO tasks was evident in the enforcement of the TEZ. Aerospace assets provided Headquarters Sector Sarajevo with NATO target lists of violations of the TEZ to be struck unless ground validation provided a reason for not doing so. UNMO resources were heavily committed to this task of validating each violation that was targeted by NATO. Moreover, some major exemptions such as the Bosnian Serb tank rebuild facility at Hadžići and the Bosnian government heavy weapons on Mount Igman had to be monitored through patrolling and repeated attempts for access. One heavy weapons collection point was actually monitored by UNMOs. Tanks transiting the TEZ had to be followed. The UNMO tasks related to the TEZ continued until the summer of 1995; a role indeed shaped by the tools of air power, both aerospace surveillance and combat aircraft.[42]

In Žepa and Goražde, UNMOs were more involved with the delivery of humanitarian assistance. Monitoring the drop zones was a task for UNMOs in both safe havens. This led in Žepa to UNMO involvement in the creation of a local force to police the drop zone. UNMOs also became involved in the evacuation of seriously sick or injured civilians. If the French aviation assets could not be deployed from Sarajevo, then UNMOs provided road transport. In the case of Žepa, in the absence of other UN staff UNMOs had to step in to stop a “healthy” individual being evacuated under medical pretences.

As had been the case in Sarajevo in February 1994, with the creation of a TEZ around Goražde UNMOs’ tasks in that Pocket became “shaped” by investigation and monitoring of violations of the TEZ identified by aerial assets and tentatively put on a target list for NATO air strikes. UNMOs never had the communications to contact NATO Combat Air Support or other air-strike resources, so could not perform the function that the JCOs had done. Instead, some nations (among them Canada) contributed teams of Forward Air Controllers/Forward Observation Officers to UNPROFOR. More immediate was the impact that the air strike of 10 April had on the tasks of all UNMOs on Bosnian Serb territory in Sector Sarajevo. All UNMO activities on the Serb side were suspended as all UNMOs were held hostage for over a week.

My conclusions drawn in an earlier paper on the influence of air power in the creation of the TEZs around Sarajevo and Goražde in the spring of 1994 still seem valid.[43] The Bosnian Serbs may well have derived military benefit from the Sarajevo ceasefire. The heavy weapons collection undertaken by the United Nations scarcely impacted on the Bosnian government’s main asset: infantry.

In the case of Goražde, air power did not stop the assault, let alone the Bosnian Serbs, from apparently achieving their tactical or, indeed, operational objectives. It is hard to see air power as anything but an aerial demonstration of NATO’s political condemnation of the Bosnian Serb aggression against the Goražde safe haven. In addition, the Goražde air strikes exposed UNPROFOR vulnerability: the use of UN personnel as human shields, which was to be exploited in 1995 by the Bosnian Serbs. For instance, they handcuffed a Canadian officer to a post outside a Serb munitions storage site near the Bosnian Serb capital of Pale.

If the influence of air strike threats on the belligerents is debatable, there can be no denying that the TEZ process – combat air power in tandem with aerial surveillance – shaped what UNMOs did. The unfortunate aspect of that is that the data about heavy weapons passed to the UNMOs to validate, first around Sarajevo starting in February 1994, then around Goražde in late April 1994, could have been on my desk when I became commander of UNMO Sarajevo in October 1993. If this NATO intelligence had been shared with my UNMOs from the beginning, then truly military observer tasks in Sector Sarajevo would have been shaped much more proactively by air power over the period October 1993 to July 1994 when so many civilians of all ethnic backgrounds died.



[1] Thomas, R. Testimony at Galić Trial, International Criminal Tribunal for the former Yugoslavia, IT-98-29(2002); Thomas, R. Testimony at Milošević Trial, International Criminal Tribunal for the former Yugoslavia, IT-02-54 (2003); Thomas, R. Testimony at Karadžić Trial,

International Criminal Tribunal for the former Yugoslavia, IT-95-5/18 (2010). Thomas R. Testimony at Mladić Trial, International Criminal Tribunal for the Former Yugoslavia, IT-09-92 (2012).

[2] Mackenzie, L. Peacekeeper: The Road to Sarajevo (Vancouver: Douglas and McIntyre, 1993). An interesting historical note is that on the creation of UNPROFOR in early 1992, the United Nations decided to place their headquarters in Sarajevo, as the organization was “looking for a nice tranquil, neutral location from which to control our operations in Croatia” (Mackenzie, Peacekeeper, 119).

[3] Thomas, R. “UN Military Observer Interpreting in a Community Setting”, in Silvana Carr, Roda Roberts, Aideen Dufour and Dini Steyn (eds) The Critical Link: Interpreters in the Community (Amsterdam: John Benjamins, 1997).

[4] See also Thomas, R. “Commanding UN Military Observers in Sector Sarajevo 1993–1994”, in In Harm’s Way: The Buck Stops Here (Kingston: Canadian Defence Academy Press, 2007), 1–25.

[5] The best pre-deployment advice the author received was this quote from Richard Round, a Canadian officer serving with the European Community Monitoring Mission.

[6] Maloney cites George Oehring, former Commander Sector South 1993–1994. The wars in Kosovo and Macedonia were yet to come in 1997. See Maloney, S. “Operation BOLSTER: Canada and the European Community Mission in the Balkans, 1991–1994”, MacNaugton Paper 10(2) (1997). Pocket refers to an ethnic group surrounded by another in these cases. Some pockets were designated safe havens by the UN.

[7] Thomas, R. Testimony at Galić Trial; Thomas, R. Testimony at Milošević Trial; Thomas, R. Testimony at Karadžić Trial.

[8] Mackenzie, Peacekeeper, 119, 257–87.

[9] Richard Round, European Community Monitor Mission op cit; deployment communications with Roy Thomas; SMO Brief, “UN Senior Military Observer Brief for Force Commander UNPROFOR”, SMO 029 19030A Dec 1993. Note that the second citation details how a Bosnian government patrol went hundreds of kilometres behind Bosnian Serb lines to destroy a farming hamlet. Serbs did not permit investigation of further damage inflicted but reported 19 such raids in the October–December 1993 time frame. NATO aerial coverage of this period can be interpreted to indicate damage to a string of villages. Further information available from author.

[10] The An-2 is a common single-engine, Soviet-era Antonov utility biplane – NATO reporting name “Colt” – similar to a bush plane, able to operating out of austere or improvised conditions.

[11] UN Security Council Resolutions 781 and 816mandated Combat Air Support and air strikes. It should be noted that UNMOs (not from Sarajevo) were deployed to monitor Serbian airfields as directed in Resolution 786. See respectively: United Nations Security Council, United Nations Security Council Resolution 781, 9 October 1992; United Nations Security Council, United Nations Security Council Resolution 786, 10 November 1992; United Nations Security Council, United Nations Security Council Resolution 816, 31 March 1993.

[12] The author can find no indication that Croatian aircraft violated Bosnian airspace.

[13] Author personally rotated in and out of Sarajevo on seven such flights.

[14] United States Air Force, “USAF Humanitarian Efforts in Bosnia-Herzegovina”, Fact Sheet, National Museum of the US Air Force. Available at: id=1402 [accessed 1 August 2012].

[15] The author personally made four trips to Ancona, Italy, from Sarajevo and back on this air bridge.

[16] United States Air Force, “USAF Humanitarian Efforts in Bosnia-Herzegovina”.

[17] Author joined UNMOs in both žepa and Goražde to observe airdrops.

[18] SMO Brief, “UN Senior Military Observer Brief for Commander on Actions to Watch [Sarajevo] Airport”, 22 January 1994.

[19] For example, SMO messages through early January dealt with the issue of alternative movement of UNMOs in case of flight cancellations.

[20] The intelligence derived from such efforts did not seem to reach the Operations Room of UNMO Sarajevo, although others were quick to ask for UNMO briefs. There is reason to believe that perhaps aircrews were briefed on this gathered intelligence. See Thomas, R. “Special Forces in the Service of Peace: Sarajevo and Haiti”, Canadian Defence Academy, unpublished.

 [21] NATO, Decision Sheet 4, 9 February 1994.

[22] NATO, Decision Sheet 4.

[23] UNMOs played a specific role in implementing General Rose’s peace plan. See Thomas, R. “Sarajevo UNMOs”, Esprit de Corps 4(1) (1994), 9.

[24] UNPROFOR laid out principles for use of air strikes as well as detailed mission procedures. See respectively Annex C and D in: United Nations Protection Force Bosnia- Herzegovina Command, Headquarters United Nations Bosnia-Herzegovina Command OPO 2/94, 19 February 1994.

[25] The Joint Commission Officers (JCOs) were actually Special Air Service (SAS) teams with the communications that permitted them to guide offensive air support strikes if required. With the establishment of weapons collection points on the Bosnian Serb side, the Serbs had to agree to have armed UN troops positioned on their territory. See Rose, Sir M. Fighting for Peace (London: Harvill Press, 1998), 57–8.

[26] UN Military Information Officer, “UN Sector Sarajevo Military Information Officer summary as of 1700 hrs. 21 February 1994” (Note that “Military Information Officer” was the UN cover title for “Sector Intelligence Officer”).

[27] UN Military Information Officer, “UN Sector Sarajevo Military Information Officer summary of Sarajevo Total Exclusion Zone violations dated 2 May 1994”.

[28] SMO Brief, “UN Senior Military Observer [SMO] Brief for Sector Commander on TEZ violations”, 5 June 1994.

[29] Four fixed-wing violators of the NFZ were shot down near Banja Luka, outside the Sector Sarajevo area of responsibility. See: NATO, “Operation Deny Flight”, NATO Allied Forces Southern Europe Fact Sheet, Naples/Brussels: NATO, 2.

[30] It is difficult to imagine a close air support mission being called in to attack a belligerent checkpoint manned by a few militiamen or irregulars, especially since the only elements with ground-to-air radio capability in Sector Sarajevo were the JCOs (i.e., Special Air Services (SAS) – see Note 37) and unknown French elements.

[31] The Yak-40 is a three-engine regional jet aircraft produced from the late 1960s to the early 1980s in the former Soviet Union – NATO reporting name: “Codling”.

[32] Thomas, “UN Military Observer Interpreting in a Community Setting”.

[33] UNMO Goražde, “UNMO Capsat message 10:48:13hrs. 11 April 1994”.

[34] UNPROFOR Sector Sarajevo, “Sequence of Events of CAS [Combat Air Support] Incident at Goražde”, 18hrs. 11 April 1994; UN Civil Affairs, “Weekly Bosnia-Herzegovina Political Assessment”.

[35] report on the detention of UNMOs outlines what happened to the UN military observers held hostage between 11 and 19 April 1994 (see: UNMO Sarajevo, “Report on Detention of UNMOs by BSA in Sarajevo from 11 April 1994 to 19 April 1994 and the Lessons Learnt”, 24 April 1994.). In addition to the 58 UNMOs, three UNPROFOR platoons at weapons collection points, an UNPROFOR light armoured squadron at the UNPROFOR base at Rajlovac, the 49 UNPROFOR personnel and 18 vehicles already held hostage near Hadžići, and two UNPROFOR checkpoints with 14 personnel and 2 vehicles were also being held hostage (see: UNPROFOR Bosnia-Herzegovina Command Forward, “Reporting Change in Attitude Toward UNPROFOR Locations”, 131610 B April, 1994).

[36] Thomas, Testimony at Galić Trial; Thomas, Testimonyat Milošević Trial; Thomas, Testimony at Karadžić Trial.

[37] Memorandum of Understanding on the Temporary Arrangement for the Town of Goražde signed by a Bosnian Serb and UNPROFOR representative”, 19 April 1994.

[38] UNPROFOR Force Commander, “Agreement on Goražde”, Fax No 5805/3510, 21 April 1994.

[39] NATO, “Decisions Taken at the Meeting of the North Atlantic Council April 22nd 1994”, NATO Press Release 94/31 (22 April 1994). Available at: [accessed 1 August 2012]. Note that the previous NATO air strikes were authorized under provision of the threat posed to UN personnel.

[40] Thomas, “Implementing the February 1994 Peace Plan for Sarajevo”, 23–4.

[41] For more details on carrying out this specific task in an area near Sarajevo International Airport, see: Thomas, R. “Passion for Football led to “94 World Cup Peace Pause” (EMC Barrhaven–Nepean, 24 June 2010), 33.

[42] For an overview of the events after the author’s departure in July 1994 see Ripley, T. Operation Deliberate Force (Lancaster: CDISS Lancaster University). It should be noted that French and American unmanned aerial vehicles were used for surveillance in 1995.

[43] Thomas, R. “Bombing in the Service of Peace: Sarajevo and Goražde, Spring 1994”, Chronicles Online Journal, 10 February 2000. Available at: [accessed 1 August 2012].


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