Croatian Defence Council in the context of "Stari Most"

The Croat–Bosniak War or Croat–Muslim War was a conflict between the Bosniak-dominated Republic of Bosnia and Herzegovina and the Croatian Republic of Herzeg-Bosnia, supported by Croatia, that lasted from 18 October 1992 to 23 February 1994.It is often referred to as a "war within a war" because it was part of the larger Bosnian War. In the beginning, the Army of the Republic of Bosnia and Herzegovina (ARBiH) and the Croatian Defence Council (HVO) fought together in an alliance against the Yugoslav People's Army (JNA) and the Army of Republika Srpska (VRS). By the end of 1992, however, tensions between the ARBiH and the HVO increased. The first armed incidents between them occurred in October 1992 in central Bosnia. The military alliance continued until early 1993, when it mostly fell apart and the two former allies engaged in open conflict.

The Croat–Bosniak War escalated in central Bosnia and soon spread to Herzegovina, with most of the fighting taking place in those two regions. The war generally consisted of sporadic conflicts with numerous short ceasefires. However, it was not an all-out war between Bosniaks and Croats and they remained allied in other regions – mainly Bihać, Sarajevo and Tešanj. Several peace plans were proposed by the international community during the war, but each of them failed. On 23 February 1994, a lasting ceasefire was agreed, and an agreement ending the hostilities was signed in Washington on 18 March 1994, by which time the HVO had suffered significant territorial losses. The agreement led to the establishment of the Federation of Bosnia and Herzegovina and the resumption of joint operations against Serb forces, which helped alter the military balance and bring the Bosnian War to an end.

The Army of the Federation of Bosnia and Herzegovina (Bosnian, Serbian, Croatian: Vojska Federacije Bosne i Hercegovine or VFBiH) was the military of the Federation of Bosnia and Herzegovina created after the 1995 Dayton Agreement. It consisted of two merging units which had been in conflict with each other during the Croat-Bosniak War: the Bosniak Army of the Republic of Bosnia and Herzegovina (ARBiH) and the Croat Croatian Defence Council (HVO). In 2005 it was integrated into Armed Forces of Bosnia and Herzegovina controlled by the Ministry of Defense of Bosnia and Herzegovina.

The Croatian Republic of Herzeg-Bosnia (Croatian: Hrvatska Republika Herceg-Bosna) was an unrecognized geopolitical entity and quasi-state in Bosnia and Herzegovina. It was proclaimed on 18 November 1991 under the name Croatian Community of Herzeg-Bosnia (Croatian: Hrvatska Zajednica Herceg-Bosna) as a "political, cultural, economic and territorial whole" in the territory of Bosnia and Herzegovina, and abolished on 14 August 1996.

The Croatian Community of Bosnian Posavina, proclaimed in northern Bosnia on 12 November 1991, was joined with Herzeg-Bosnia in October 1992. In its proclaimed borders, Herzeg-Bosnia encompassed about 30% of the country, but did not have effective control over the entire territory as parts of it were lost to the Army of Republika Srpska (VRS) at the beginning of the Bosnian War. The armed forces of Herzeg-Bosnia, the Croatian Defence Council (HVO), were formed on 8 April 1992 and initially fought in an alliance with the Army of the Republic of Bosnia and Herzegovina. Their relations deteriorated throughout late 1992, which led to the Croat–Bosniak War.

Bosnian mujahideen (Bosnian: Bosanski mudžahedini), also called El Mudžahid, were foreign Muslim volunteers who fought on the Bosnian Muslim side during the Bosnian War (1992–95). They first arrived in central Bosnia in the latter half of 1992 with the aim of helping their Bosnian Muslim co-religionists in fights against Serb and Croat forces. Initially they mainly came from Arab countries, later from other Muslim-majority countries. Estimates of their numbers vary from 500 to 5,000 with most estimates in the 1,000–2,000 range.

Operation Storm (Serbo-Croatian: Operacija Oluja / Операција Олуја) was the last major battle of the Croatian War of Independence and a major factor in the outcome of the Bosnian War. It was a decisive victory for the Croatian Army (HV), which attacked across a 630-kilometre (390 mi) front against the self-declared proto-state Republic of Serbian Krajina (RSK), and a strategic victory for the Army of the Republic of Bosnia and Herzegovina (ARBiH). The HV was supported by the Croatian special police advancing from the Velebit Mountain, and the ARBiH located in the Bihać pocket, in the Army of the Republic of Serbian Krajina's (ARSK) rear. The battle, launched to restore Croatian control of 10,400 square kilometres (4,000 square miles) of territory - representing 18.4% of the territory it claimed - and Bosniak control of Western Bosnia, was the largest land battle that took place in Europe between the end of World War II and the 2022 Russian invasion of Ukraine. Operation Storm commenced at dawn on 4 August 1995 and was declared complete on the evening of 7 August, despite significant mopping-up operations against pockets of resistance lasting until 14 August.

Operation Storm was a strategic victory in the Bosnian War, effectively ending the siege of Bihać and placing the HV, Croatian Defence Council (HVO), and the ARBiH in a position to change the military balance of power in Bosnia and Herzegovina through the subsequent Operation Mistral 2. The operation was conceived on HV and HVO advances made during Operation Summer '95, when strategic positions allowing the rapid capture of the RSK capital Knin were gained, and on the continued arming and training of the HV since the beginning of the Croatian War of Independence, when the RSK was created during the Serb Log Revolution and Yugoslav People's Army intervention. The operation itself followed an unsuccessful United Nations (UN) peacekeeping mission and diplomatic efforts to settle the conflict.