By July 1995, the efforts of the United Nations to bring peace to Yugoslavia looked doomed to failure, and its international credibility was rapidly diminishing. The UN would make firm declarations to the international community, and when challenged by the Bosnian Serbs would fall back and accede to their demands. While the UN’s position became increasingly undermined with each atrocity and humiliation on the ground, the effect on the Bosnian Serbs was quite the opposite. The fall of Srebrenica greatly encouraged them to continue their aggression against the safe areas, and a few weeks later on 25 July 1995, Mladic’s men managed to seize another safe area – Zepa. Once more, the international community appeared paralysed by events on the ground in Bosnia-Hercegovina, and even the UN Human Rights Advocate, Tadeusz Mazowiecki, resigned in protest over the flagrant breaches of human rights. However, specific operational measures were under discussion that would radically transform the situation. As Zepa fell to the advancing Bosnian Serbs, the North Atlantic Council (the decision-making body within NATO) agreed on a new policy of air strikes as part of a sustained campaign, rather than close air support operations, to protect the remaining safe areas of Bihac, Tuzla and Sarajevo. In concert with the United Nations, the command and control system to initiate such a response was also changed, giving the ‘key’ to the Force Commander in theatre, or in his absence to the UNPROFOR Commander in Bosnia-Hercegovina. In simple terms, if the key was ‘turned’ then action would occur immediately – not just one or two bombs, but a sustained offensive.
Events on the ground were also about to change for different strategic reasons. The official and unofficial aid (civilian and military) that the United States had given to the Croatian Army was now about to bear fruit. On 4 August, the revitalised and US-trained Croatian forces initiated Operation Storm, or Oluja, which was designed to decisively capture the Croatian Serb area of the Krajina. The Croats had built up an army of 200,000 soldiers for this operation, and attacked in a pincer movement with a heavy emphasis on the capture of the strategically important capital, Knin. Following a lightning heavy bombardment of Serb positions, the Croatian forces moved forward with remarkable ease. The Croatian Serb forces had about 40,000 troops and 400 tanks to defend the region, but these were caught out by the speed and direction of the offensive. In just three days, Republika Srpska Krajina was largely overrun by the victorious Croatian Army, and the capital of Knin captured with almost 200,000 Serbs fleeing into Bosnia-Hercegovina. Despite assurances from President Tudjman that civilians would not be harmed, there were widespread indications of atrocities against the Serbs who stayed behind, and entire villages were razed to the ground.
This tremendous military victory rapidly altered the strategic and diplomatic context in the Balkans, and the Croatian forces and their Bosniac allies in Bihac began to make significant in-roads into the Serb-controlled regions.
The trigger for the use of decisive force against the Bosnian Serbs by NATO forces was the firing of five mortar shells at the busy Markale Market on the morning of 28 August 1995. Thirty-seven people were killed and around 90 wounded in the attack. Interestingly, a year earlier, an identical attack in which 68 people were killed had prompted the then UNPROFOR commander, General Rose, to blame Bosniacs as a result of a flawed forensic report. This time, the report into the shelling clearly identified that the shells had originated from the Bosnian Serb positions around Lukavica. Unlike his predecessor, General Sir Rupert Smith did not solely pursue the negotiations option in the aftermath of the massacre with a view to seeking another fragile agreement. Instead, the British commander exploited the situation to bring about a resolution once and for all. By fortunate coincidence, the UN Force Commander in Zagreb was out of theatre, and so the ‘key’ to initiate air strikes resided in the hands of General Smith.
One constraint on the immediate recourse to air strikes was the presence of UN forces passing through Bosnian Serb territory near Gorazde. It is important to note that Serb tactics of taking hostages after a close air support strike had not been lost on UNPROFOR, and consequently in the weeks leading up to late August 1995 NATO had deliberately withdrawn its forces from exposed positions. Having received the report into the attack on Sarajevo, General Smith employed a clever dual-track psychological approach to ensure the safe passage of his troops through the Bosnian Serb lines. First, during a phone call with General Mladic, the UNPROFOR commander neglected to mention that he now knew who had fired the mortars and that he was planning direct military action. Consequently, Mladic was lulled into a false sense of security, and let the UN forces pass out of the territory unhindered. Secondly, General Smith released a statement to the press that was very vague on the subjects of either who was to blame for the attack that morning, or what the response of the international community would be. To any seasoned observer of Balkan affairs on the night of 28 August, it looked like the UN would once more revert to inactivity, and acquiesce to yet another atrocity.
At 2000hrs on 28 August 1995, General Sir Rupert Smith turned his key. He did so without consulting the UN (who found out about this decision six hours later) or the nations who were contributing troops to UNPROFOR, and talked instead with the head of NATO’s Southern Command, who would initiate the air strikes. Both men were in agreement that the air strikes would commence as soon as NATO forces were ready and the weather improved. At 0300hrs on 30 August, Operation Deliberate Force began in earnest, with the aim of significantly degrading the ability of the Bosnian Serb forces entrenched around Sarajevo to harm either the civilians or UNPROFOR forces. The Rapid Reaction Force was an essential component of the strategy to neutralise Bosnian Serb artillery positions, and came equipped with heavy artillery. On the first night of operations they fired 600 rounds of heavy calibre, high explosive ordnance on Bosnian Serb artillery positions around Sarajevo. UNPROFOR guns located on Mount Igman bracketed 19 Bosnian Serb positions with devastatingly accurate shell-fire in order to coerce them into withdrawing out of the 20km exclusion zone around Sarajevo. The terms under which Operation Deliberate Force would be halted were unambiguous – the Bosnian Serbs must respect the safe zones around the remaining safe areas, and stop fighting not only in these areas, but across the entire country. The cost to the NATO forces on the first night of operations was extremely light, with one French Mirage aircraft shot down and some ineffective small arms fire being directed at UNPROFOR positions.
Negotiations continued throughout the bombing, and a lull in the air strikes on 31 August caused by bad weather allowed the Force Commander, General Janvier (who had returned to the region), to implement a strategic pause in operations on 1 September in order to initiate talks with General Mladic at Zvornik. In addition, General Smith used this period to open up the road between Sarajevo and its airport on 2 September, and warned the Bosnian Serbs that if they prevented the free flow of traffic, the consequences would be extremely severe. A day later he also opened up a land route from the city to Butmir. In effect, General Smith had broken the siege of Sarajevo and people could move freely on these routes, without fear of roadblock or shootings, for the first time in three years. The talks with Mladic and the Bosnian Serb leadership predictably failed, and air strikes continued on 5 September. To the consternation of the UN hierarchy, UNPROFOR started issuing statements that they would ‘cripple’ the military capabilities of the Bosnian Serbs. In concert with these threats, NATO aircraft started to hit targets outside of Sarajevo (labelled ‘Option 3’) from 6 September onwards, mainly because they had run out of the so-called Option 2 targets around the city. These Option targets were Serbian positions of military and economic value, from anti-aircraft missile sites to communications centres that included television and radio transmitters. These could be targeted with an array of weapons, from precision-guided munitions to ‘dumb’ bombs. Again, negotiations between the three sides continued throughout the bombing, and the United States diplomat Richard Holbrooke interfaced with the highest levels of the three political structures. On 10 September, NATO increased the pressure on the Bosnian Serbs by firing 13 Tomahawk missiles at the air defence sites around Banja Luka. Bit by bit, General Mladic’s forces were being taken apart by NATO forces, finally dispelling the prevalent myth that hundreds of thousands of troops would be required to bring the Bosnian Serbs under control. By 14 September the negotiations had made surprising progress, and once more a pause was put into effect regarding the air strikes. The Bosnian Serbs completely complied with all the terms set out by the UN, and Operation Deliberate Force was formally ended on 21 September.
NATO aircraft flew over 3000 sorties in support of Operation Deliberate Force, and attacked more than 60 targets on the ground. In concert with UNPROFOR artillery units, these attacks demonstrated that the Bosnian Serb forces were little more than a paper tiger. The military situation for the Bosnian Serbs went from bad to worse throughout this offensive, as Croatian and Bosniac forces captured more territory. The proportion of Bosnia-Hercegovina controlled by the Bosnian Serbs fell rapidly by around 20 per cent. It became increasingly clear that the Bosnian Serb military leadership was out of its league. General Mladic’s military reputation was quickly exposed by General Sir Rupert Smith as one built on bluff and fighting much weaker forces. General Smith was a man with vastly more military experience, who had led an armoured division in the Gulf War of 1991. It was a moral and military victory for a soldier who avoided the limelight, and never forgot his humanity. Operation Deliberate Force remains a little-known example of how a seemingly intractable conflict can be resolved though the robust interpretation of a UN peacekeeping mandate.