The Ten-Day War (Slovene: Desetdnevna vojna), or the Slovenian War of Independence (Slovene: Slovenska osamosvojitvena vojna), was a brief armed conflict that followed Slovenia's declaration of independence from Yugoslavia on 25 June 1991. It was fought between the Slovenian Territorial Defence and the Slovenian National Police Force on one side, and the Yugoslav People's Army (JNA) on the other. It lasted from 27 June 1991 until 7 July 1991, when the Brioni Accords were signed.
It was the second of the Yugoslav Wars to start in 1991, following the Croatian War of Independence, and by far the shortest of the conflicts with fewest overall casualties. The war was brief because the JNA, dominated by Serbs and Montenegrins, although still made up of all the nationalities of Yugoslavia, did not want to waste resources on this campaign. Slovenia was considered "ethnically homogeneous" and therefore of no interest to the Yugoslav government. The military was preoccupied with the fighting in Croatia, where the Serb and Montenegrin majority in Yugoslavia had greater territorial interests. In the BBC documentary The Death of Yugoslavia, which used archival footage, Slobodan Milošević, President of Serbia, is recorded stating that "I was against using the Yugoslav Army in Slovenia", while Borisav Jović, President of the Presidency of Yugoslavia, stated that, "With Slovenia out of the way, we could dictate the terms to the Croats."
After the death of Yugoslav president Josip Broz Tito in 1980, underlying political, ethnic, religious, and economic tensions within Yugoslavia surfaced. In 1989 Slobodan Milošević, Chairman of the Central Committee of the League of Communists of Serbia since 1986, became President of Serbia, the largest and most populous of the six Yugoslav republics. Mateja Sednak explains,As... Milošević moved to consolidate power by centralizing the state, the governments of the other republics sought to loosen the central grip on power by devolving as much constitutional power as possible to each of the republics and autonomous provinces.
A series of disagreements among delegates persisted until four of the six Yugoslav republics each made decisions to seek independence from Yugoslavia. Slovenia was among the republics aiming for independence, and it was subsequently recognised by Germany and the Vatican.
In April 1990, Slovenia held its first democratic multi-party elections, won by the DEMOS coalition.
On 23 December 1990, Slovenia held a referendum, which passed with 88.5% of overall electorate supporting independence (95.7% of votes cast), with a turnout of 93.3%. The Slovenian government was well aware that the federal government in Belgrade might seek to use military force to quash Slovenia's move towards independence. Immediately after the Slovenian elections, the JNA announced a new defence doctrine that would apply across the country. The Tito-era doctrine of "General People's Defence", in which each republic maintained a territorial defence (TO), was to be replaced by a centrally directed system of defence. The republics would lose their role in defence matters, and their TOs would be disarmed and subordinated to the JNA's headquarters in Belgrade.
The Slovenian government resisted these moves and successfully ensured that the majority of Slovenian Territorial Defence equipment was kept out of the hands of the JNA. It also declared in a constitutional amendment passed on 28 September 1990 that its TO would be under the sole command of the Slovenian government. At the same time, the Slovenian government set up a secret alternative command structure, known as the Manoeuvre Structures of National Protection (Manevrska struktura narodne zaščite, or MSNZ). This was an existing but antiquated institution, unique to Slovenia, which was intended to enable the republic to form an ad hoc defence structure, akin to a home guard. It was of negligible importance prior to 1990, with antiquated weapons and few members. However, the DEMOS-led government realised that the MSNZ could be adapted to provide a parallel organisation to the TO that would be entirely in the hands of the Slovenian government.
When the JNA tried to take control of the Slovenian Territorial Defence, the TO's command structure was simply replaced by that of the parallel MSNZ. Between May and October 1990, some 21,000 Slovenian Territorial Defence and police personnel were secretly mobilised into the MSNZ command structure, of which the federal government was wholly unaware. The Slovenian government also undertook detailed planning of a military campaign against the JNA, which resulted in the production of an operational and tactical plan by November 1990 – over seven months before the conflict actually began.
The Slovenes were aware that they would not be able to deter the JNA's forces for an extended period of time. Under Defence Minister Janez Janša, they adopted a strategy based on an asymmetric warfare approach. TO units would carry out a guerrilla campaign, using anti-tank weapons and anti-aircraft missiles to ambush the JNA's units. Tank columns could be trapped by destroying the lead and rear vehicles in favourable terrain – for instance, on a narrow mountain road where room for manoeuvre was limited – enabling the rest to be dealt with more easily. In preparation for this, the Slovenian government covertly bought lightweight missile systems from foreign suppliers, notably the SA-7 Grail (Strela) anti-aircraft missile and the German-designed Armbrust anti-tank system. Hit-and-run and delaying tactics were to be preferred and frontal clashes were to be avoided since in such situations the JNA's superior firepower would have been very difficult to overcome.
Slovenia and Croatia passed their acts of independence on 25 June 1991. This "advance" on the date of independence was a critical element of the Slovenian plan to gain an early advantage in the expected conflict. The Slovenian government fully expected the Yugoslav military to respond with force on the day of the declaration of independence or shortly afterwards. By secretly advancing the date by 24 hours, the Slovenians caught the Yugoslav government off guard, which had set 26 June as the date for its move.
Although the JNA was adamantly opposed to Slovenian independence, it was divided about what to do. The JNA Chief of Staff, Colonel-General Blagoje Adžić, advocated a large-scale military operation to remove the Slovenian government and bring "healthy forces" to power in the republic. His political superior, the Yugoslav defence minister, General of the Army Veljko Kadijević, insisted on a more cautious approach – essentially a show of force that would convince the Slovenian government to back down on its declaration of independence. After some debate, Kadijević got his way.
It is unclear how much the civilian members of the Yugoslav government were involved in the decision to resort to force in Slovenia. Ante Marković, the president of the Federal Executive Council (equivalent to prime minister) is reported to have said that the federal government had not been informed of the Army's actions.
On the morning of 26 June, units of the JNA's 13th Corps left their barracks in Rijeka, Croatia, to move towards Slovenia's borders with Italy. The move immediately led to a strong reaction from local Slovenians, who organized spontaneous barricades and demonstrations against the JNA's actions.
By this time, the Slovenian government had already put into action its plan to seize control of the republic's border posts and the international airport at Brnik. The personnel manning the border posts were, in most cases, already Slovenians, so the Slovenian take-over mostly simply amounted to changing of uniforms and insignia, without any fighting. This was undertaken, in the words of Janez Janša, to "establish our sovereignty in the key triangle, border-customs-air control". It also had important practical effects. The border crossings were a major source of revenue. In addition, by taking control of the borders, the Slovenians were able to establish defensive positions against an expected JNA attack. This meant that the JNA would have to fire the first shot. It was fired on 26 June at 14:30 in Divača by an officer of the JNA.