Operation Mistral 2, officially codenamed Operation Maestral 2, was a Croatian Army (HV) and Croatian Defence Council (HVO) offensive in western Bosnia and Herzegovina on 8–15 September 1995 as part of the Bosnian War. Its objective was to create a security buffer between Croatia and positions held by the Bosnian Serb Army of Republika Srpska (VRS). The operation also spearheaded a Herzeg-Croat led move to compromise the occupation of the largest Bosnian Serb-held city, Banja Luka, by capturing the towns of Jajce, Šipovo and Drvar. Thus jeopardizing the operations capacity of Banja Luka and ultimately leading to its recapture. The combined HV and HVO forces were under the overall command of HV Major General Ante Gotovina.
The operation commenced during a North Atlantic Treaty Organization (NATO) air campaign against the VRS codenamed Operation Deliberate Force, targeting VRS air defences, artillery positions and storage facilities largely in the area of Sarajevo, but also elsewhere in the country. Days after commencement of the offensive, the VRS positions to the right and to the left of the HV and the HVO advance were also attacked by the Army of the Republic of Bosnia and Herzegovina (ARBiH) in Operation Sana. The offensive achieved its objectives and set the stage for further advances of the HV, HVO and ARBiH towards Banja Luka, contributing to the resolution of the war.
There is disagreement among scholars as to whether the offensive, together with Operation Sana, or NATO airstrikes contributed more towards the resolution of the Bosnian War, and to what extent ARBiH, HVO and HV advances were aided by NATO airstrikes. Operation Mistral 2 resulted in the deaths of hundreds of Bosnian Serb civilians, as well as the displacement of tens of thousands of others. In 2011, five former Croatian military personnel were convicted of war crimes for the summary execution of five Bosnian Serb soldiers and a civilian during the operation. In 2016, Bosnian Serb officials filed a criminal complaint against the Croatian Minister of Defence, Damir Krstičević, alleging that he had committed war crimes during the offensive.
Background As the Yugoslav People's Army (Jugoslovenska narodna armija – JNA) withdrew from Croatia following the acceptance and start of implementation of the Vance plan, its 55,000 officers and soldiers born in Bosnia and Herzegovina were transferred to a new Bosnian Serb army, which was later renamed the Army of Republika Srpska (Vojska Republike Srpske – VRS). This re-organisation followed the declaration of the Serbian Republic of Bosnia and Herzegovina on 9 January 1992, ahead of the referendum on the independence of Bosnia and Herzegovina that took place between 29 February and 1 March 1992. This declaration would later be cited by the Bosnian Serbs as a pretext for the Bosnian War. Bosnian Serbs began fortifying the capital, Sarajevo, and other areas on 1 March 1992. On the following day, the first fatalities of the war were recorded in Sarajevo and Doboj. In the final days of March, Bosnian Serb forces bombarded Bosanski Brod with artillery, resulting in a cross-border operation by the Croatian Army (Hrvatska vojska – HV) 108th Brigade. On 4 April 1992, JNA artillery began shelling Sarajevo. There were other examples of the JNA directly supported the VRS, such as during the capture of Zvornik in early April 1992, when the JNA provided artillery support from Serbia, firing across the Drina River. At the same time, the JNA attempted to defuse the situation and arrange negotiations elsewhere in the country.
The JNA and the VRS in Bosnia and Herzegovina faced the Army of the Republic of Bosnia and Herzegovina (Armija Republike Bosne i Hercegovine – ARBiH) and the Croatian Defence Council (Hrvatsko vijeće obrane – HVO), reporting to the Bosniak-dominated central government and the Bosnian Croat leadership respectively, as well as the HV, which occasionally supported HVO operations. In late April 1992, the VRS was able to deploy 200,000 troops, hundreds of tanks, armoured personnel carriers (APCs) and artillery pieces. The HVO and the Croatian Defence Forces (Hrvatske obrambene snage – HOS) could field approximately 25,000 soldiers and a handful of heavy weapons, while the ARBiH was largely unprepared with nearly 100,000 troops, small arms for less than a half of their number and virtually no heavy weapons. Arming of the various forces was hampered by a United Nations (UN) arms embargo that had been introduced in September 1991. By mid-May 1992, when those JNA units which had not been transferred to the VRS withdrew from Bosnia and Herzegovina to the newly declared Federal Republic of Yugoslavia, the VRS controlled approximately 60 percent of Bosnia and Herzegovina. The extent of VRS control was extended to about 70 percent of the country by the end of 1992.
Prelude By 1995, the ARBiH and the HVO had developed into better-organised forces employing comparably large numbers of artillery pieces and good defensive fortifications. The VRS was not capable of penetrating their defences even where its forces employed sound military tactics, for instance in the Battle of Orašje in May and June 1995. After recapture of the bulk of the Republic of Serb Krajina (the Croatian Serb-controlled areas of Croatia) in Operation Storm in August 1995, the HV shifted its focus to western Bosnia and Herzegovina. The shift was motivated by a desire to create a security zone along the Croatian border, establish Croatia as a regional power and gain favours with the West by forcing an end to the Bosnian War. The government of Bosnia and Herzegovina welcomed the move as it contributed to their goal of gaining control over western Bosnia and the city of Banja Luka—the largest city in the Bosnian Serb-held territory.
In the final days of August 1995, NATO launched Operation Deliberate Force—an air campaign targeting the VRS. This campaign was launched in response to the second Markale massacre of 28 August, which came on the heels of the Srebrenica massacre. Airstrikes began on 30 August, initially targeting VRS air defences, and striking targets near Sarajevo. The campaign was briefly suspended on 1 September and its scope was expanded to target artillery and storage facilities around the city. The bombing resumed on 5 September, and its scope extended to VRS air defences near Banja Luka by 9 September as NATO had nearly exhausted its list of targets near Sarajevo. On 13 September, the Bosnian Serbs accepted NATO's demand for the establishment of an exclusion zone around Sarajevo and the campaign ceased.
Order of battle As the NATO bombing generally targeted VRS around Sarajevo, western Bosnia remained relatively calm following Operation Storm, except for probing attacks launched by the VRS, HVO or ARBiH near Bihać, Drvar and Glamoč. At the time the HV, HVO and ARBiH were planning a joint offensive in the region. The main portion of the offensive was codenamed Operation Maestral (Croatian name for maestro wind), or more accurately Operation Maestral 2. Within a month, the HV and HVO had planned an operation to capture the towns of Jajce, Šipovo and Drvar, and position their forces to threaten Banja Luka. Major General Ante Gotovina was placed in command of the combined HV and HVO forces earmarked for the offensive.
The forces were deployed in three groups. Operational Group (OG) North, tasked with capturing Šipovo and Jajce, consisted of 11,000 troops and included the best units available to Gotovina—the 4th Guards and the 7th Guards Brigades, the 1st Croatian Guards Brigade (1. hrvatski gardijski zdrug – 1st HGZ) of the HV and three HVO guards brigades. The rest of the force was organised into OG West and OG South, and consisted of five HV Home Guard regiments and three reserve infantry brigades. These two groups were to pin down the troops of the VRS 2nd Krajina Corps in the vicinity of Drvar, and attempt to advance on the town. Once OG North had completed its tasks, it was to turn back and capture Drvar. Gotovina's forces were deployed between the ARBiH 5th Corps on their left, and the 7th Corps on their right. The ARBiH forces were to advance on the flanks of the HV and the HVO, in a separate but coordinated offensive codenamed Operation Sana.
In the area of the combined HV and HVO offensive, the VRS had its 2nd Krajina Corps, commanded by Major General Radivoje Tomanić, and the 30th Infantry Division of the 1st Krajina Corps, commanded by Major General Momir Zec. Tomanić, who set up his headquarters in Drvar, was in overall command in western Bosnia. Tomanić and Zec commanded a combined force of approximately 22,000 troops. They considered the ARBiH to be a greater threat in the area and only deployed between 5,000 and 6,000 troops directly against the HV, consisting of one motorised and six infantry or light infantry brigades fielded along the frontline and one brigade in reserve.
+HV and HVO order of battle. Group Unit Notes North 4th Guards Brigade HV units, under direct command of Major General Ante Gotovina; The 81st Battalion not deployed initially 7th Guards Brigade 1st Croatian Guards Brigade General Staff Reconnaissance Sabotage Company 81st Guards Battalion 1st Guards Brigade HVO units, under command of Brigadier Željko Glasnović 2nd Guards Brigade 3rd Guards Brigade 60th Guards Airborne Battalion 22nd Sabotage Detachment Special police of the Ministry of Interior of Herzeg-Bosnia South 6th Home Guard Regiment HV units, under command of Brigadier Ante Kotromanović 126th Home Guard Regiment 141st Infantry Brigade West 7th Home Guard Regiment HV units, under command of Brigadier Mladen Fuzul 15th Home Guard Regiment 134th Home Guard Regiment 142nd Home Guard Regiment 112th Infantry Brigade 113th Infantry Brigade
+VRS order of battle Area Unit Notes Drvar 1st Drvar Light Infantry Brigade South and southwestern approaches to Drvar 1st Drina Light Infantry Brigade Southeastern approaches to Drvar; Units formed from elements drawn from most of the Drina Corps brigades and deployed to western Bosnia as reinforcements 2nd Drina Light Infantry Brigade 3rd Drina Light Infantry Brigade 9th Grahovo Light Infantry Brigade Remnants only; The bulk of the brigade had been destroyed in Operation Summer '95Mlinište–Vitorog 3rd Serbian Brigade Reinforced brigade 7th Kupres-Šipovo Motorised Brigade Augmented by elements of the 30th Division 1st Armoured Brigade One battalion only; Not initially deployed
Timeline
First stage: 8–11 September
The first stage of the offensive was planned to overcome VRS defences extending across mountains north of Glamoč, guarding southern approaches to Šipovo and Jajce. The attack was launched in the morning of 8 September. The 7th and the 4th Guards Brigades spearheaded the attack, striking towards the Mlinište Pass and Jastrebnjak Hill respectively. The first line of VRS defences was breached by 10:00, which allowed the 1st HGZ to push through the 4th Guards Brigade and outflank Mount Vitorog and the particularly strong VRS defences there. The 1st HGZ was quickly reinforced by the 60th Guards Battalion and the special police in attacks against the VRS positions on Vitorog. The farthest advance achieved on the initial day of the offensive was achieved by the 4th Guards Brigade, which advanced . The 7th Guards Brigade and the 1st HGZ advanced considerably less distance, while the supporting efforts of OG South and OG West launched that day against Drvar made little progress.
On 9 September, the HV and HVO defeated the bulk of the main VRS defences of the 3rd Serbian and 7th Motorised Brigades, achieving a key breakthrough. The 1st HGZ pushed back the VRS from Vitorog, and the 7th Guards Brigade advanced , capturing the Mlinište Pass, while the 4th Guards Brigade secured