The Ten-Day War, sometimes called the Slovenian War (Slovenian: Slovenska osamosvojitvena vojna, "Slovenian Independence War" or desetdnevna vojna "Ten-Day War"), was a brief military conflict between Slovenia and Yugoslavia in 1991 following Slovenia's declaration of independence.

Background
On 23 December 1990, Slovenia held a referendum on independence which passed with 88% of the vote. The Slovenian government was well aware that the federal government in Belgrade might seek to use military force to rein in Slovenia's moves towards independence. Immediately after the Slovenian elections, the Yugoslav People's Army (JNA) announced that a new defence doctrine would apply across the country. The Tito-era doctrine of "General People's Defence", in which each republic maintained a territorial defence force (teritorialna obramba or TO), would henceforth 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 JNA headquarters in Belgrade.
The Slovenian government resisted these moves, successfully ensuring that the majority of Slovenian TO 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 TO, the TO's command structure was simply replaced by that of the parallel MSNZ. Between May and October 1990, some 21,000 TO 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 well aware that they would not be able to resist the JNA for a very long 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 JNA 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 tackled 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, but frontal clashes were to be avoided; in such situations, the JNA's superior firepower would have been very difficult to overcome.
On the diplomatic front, neither the European Community nor the United States were willing to recognise the independence of Slovenia and strongly advocated the continuation of a unified Yugoslavia. The Slovenian government sought international assistance in negotiating a peaceful breakup of Yugoslavia but was rebuffed by Western countries that said they preferred to deal with a single federation rather than numerous small states. However, the Slovenes contended that they had no choice in pushing for independence, given a perceived lack of commitment to democratic values on the part of the Belgrade authorities.

Preparations for war
Slovenia unexpectedly declared independence on 25 June 1991, although it had previously announced that it would declare independence on 26 June. 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 wrongfooted the Yugoslav government, which had set 26 June as the date for its move.

Conflict
On the morning of 26 June, units of the Yugoslav People's Army'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 Slovenes, who organised spontaneous barricades and demonstrations against the JNA's actions. There was, as yet, no fighting, and both sides appeared to have an unofficial policy of not being the first to open fire.
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 Slovene 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." . 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 shots, which would enable the Slovenians to portray the Yugoslav military as aggressors.

26 June 1991
Further JNA troop movements took place in the early hours of 27 June. A unit of the JNA's 306th Anti-Aircraft Regiment, based in Karlovac, Croatia, crossed the Slovenian border at Metlika. A few hours later, a column of tanks and armoured personnel carriers of the JNA 1st Armoured Brigade left their barracks at Vrhnika near the Slovenian capital Ljubljana, heading for the airport at Brnik. They arrived a few hours later and took control of the facilities. It is worth mentioning here that as JNA was the federal army its forces were placed in various places within the federal republics including Slovenia. To the east, JNA units left Maribor heading for the nearby border crossing at Šentilj and the border town of Dravograd further west. Yugoslav Air Force aircraft dropped leaflets over various parts of Slovenia bearing the somewhat contradictory messages "We invite you to peace and cooperation!" and "All resistance will be crushed."
The Slovenian government had received warnings that the JNA would use helicopters to ferry special forces troops to strategic locations. It issued a warning to the JNA's 5th Military Command District in Zagreb that if helicopters continued to be used they would be shot down. The warning was disregarded by the JNA leadership, which still believed that the Slovenians would back down rather than fight. This was, however, a disastrous miscalculation. In the afternoon of 27 June, the Slovenian TO shot down two JNA helicopters over Ljubljana, killing the occupants (one of whom, ironically, was a Slovenian pilot, as JNA's forces consisted of nationals from all the republics).
The TO also took up position around JNA barracks in various locations, effectively besieging them, and launched a series of attacks on JNA forces across Slovenia. At Brnik, a TO unit attacked the JNA troops holding the airport, and at Trzin a firefight developed in which four JNA soldiers and one TO soldier were killed and the remainder of the JNA unit was forced to surrender. Attacks were also launched by Slovenian TO units on JNA tank columns at Pesnica, Ormož and Koseze, near Ilirska Bistrica. A tank column from the JNA's 32nd Mechanised Brigade, advancing from Varaždin in Croatia, was blocked at Ormož near the Slovenian border and found itself unable to break through a Slovenian barricade.
Despite the confusion and fighting, the JNA nonetheless successfully accomplished much of its military mission. By midnight on 27 June it had captured all of the crossings along the Italian border, all but three crossings on the Austrian border and several of the new crossing points established along Slovenia's border with Croatia. However, many of its units were still stuck in vulnerable positions across Slovenia.

27 June 1991
During the night of 27–28 June, Slovenian TO units were ordered to undertake a general offensive against the JNA. The Slovenian defence ministry ordered:
At all locations where RS [Republic of Slovenia] armed forces have the tactical advantage, offensive actions against enemy units and facilities will be carried out. The enemy will be summoned to surrender, the shortest deadline possible for surrender given and action taken using all available weapons. While in action, the necessary arrangements will be made to evacuate and protect the civilians.
Further fighting took place throughout the day. The JNA tank column that had been attacked at Pesnica the previous day was blocked by impromptu barricades of Slovenian trucks at Strihovec, a few miles short of the border with Austria, where it again came under attack by TO personnel and Slovenian police. The Yugoslav Air Force mounted two attacks in support of the JNA forces at Strihovec, killing four truck drivers. At Medvedjek in central Slovenia, another JNA tank column came under attack at a truck barricade, where air raids killed six truck drivers. Heavy fighting broke out at Nova Gorica on the border with Italy, where the Slovenian Special Forces destroyed three JNA T-55 tanks and captured three more. Four JNA soldiers were killed and nearly 100 more surrendered.
The border crossing at Holmec was captured by Slovenian forces, with two fatalities on the Slovenian side and three on the JNA side; 91 JNA soldiers were captured. The JNA barracks at Bukovje near Dravograd were attacked by TO units and a JNA weapons depot at Borovnica fell to the Slovenian TO, significantly improving the Slovenians' supply of weapons. The Yugoslav Air Force carried out attacks at a number of locations across the country, most notably at Brnik Airport, where two Austrian journalists were killed and four Adria Airways airliners were seriously damaged. The Air Force also attacked the Slovenian military headquarters at Kočevska Reka and flew sorties against radio and television transmitters at Krim, Kum, Trdinov vrh and Nanos in an attempt to silence the Slovenian government's broadcasts.
By the end of the day, the JNA still held many of its positions but was rapidly losing ground. It was already beginning to suffer problems with desertions — many Slovenian members of the JNA quit their units or simply changed sides - and both the troops on the ground and the leadership in Belgrade appeared to have little idea of what to do next.

28 June 1991
The outbreak of the war galvanised diplomatic efforts by the European Community to find an end to the crisis. Three EC foreign ministers met with Slovenian and Yugoslav government representatives in Zagreb during the night of 28 June-29 June and agreed on a ceasefire plan, but this was not put into practice. In the morning, the Slovenes achieved several significant military successes. The JNA troops at Brnik Airport surrendered to Slovenian TO forces, who had surrounded the facility overnight. In the north, several JNA tanks were captured near Strihovec and later reorganised into a TO tank company. JNA special forces attempted a maritime landing at Hrvatini but were ambushed and repulsed by the Slovenians. The JNA-held border crossings at Vrtojba and Šentilj also fell to the Slovenians, who seized the federal troops' weapons and tanks, providing a much-needed boost to their arsenal.
The JNA issued an ultimatum to Slovenia, demanding an immediate cessation of hostilities by 0900 on 30 June. In response, the Slovenian Assembly adopted a resolution calling for a peaceful solution to the crisis that did not jeopardise Slovenian independence, and rejected the JNA ultimatum.

29 June 1991
Skirmishing continued in several places during the day. Slovenian forces captured the strategic Karavanke Tunnel under the Alps on the border with Austria and captured nine JNA tanks near Nova Gorica. The entire JNA garrison at Dravograd - 16 officers and 400 men, plus equipment — surrendered, and the garrisons at Tolmin and Bovec also fell to the Slovenians. The weapons captured from the garrisons were quickly redistributed to the Slovenian forces.

30 June 1991
More skirmishes took place, with Slovenian forces capturing a JNA facility at Nova Vas, south of Ljubljana. The JNA's ammunition dump at Črni Vrh caught fire and was destroyed in a massive explosion, damaging much of the town. However, the Slovenians successfully captured depots at Pečovnik, Bukovžlak and Zaloška Gorica, taking possession of some 70 truckloads of ammunition and explosives.
The JNA 306th Light Air Defence Artillery Regiment's column retreated from its exposed position at Medvedjek and headed into the Krakovski forest (Krakovski gozd) near the Croatian border. It ran into a blockade near the town of Krško and was surrounded by Slovenian forces, but refused to surrender, probably hoping for help from a relief column.
In the meantime, the JNA's leadership sought permission to change the tempo of its operations. Defence Minister Veljko Kadijević informed the Yugoslav cabinet that the JNA's first plan - a limited operation to secure Slovenia's border crossings had failed, and that it was time to put into operation the backup plan of a full-scale invasion and imposition of military rule in Slovenia. However, the cabinet — headed at the time by Serbia's Borisav Jović — refused to authorise such an operation. The JNA Chief of Staff, General Blagoje Adzić, was furious and publicly denounced "the federal organs [which] continually hampered us, demanding negotiations while they [the Slovenians] were attacking us with all means."

1 July 1991
The heaviest fighting of the war to date took place during 2 July, which proved a day of disasters for the JNA. The JNA tank column in the Krakovski forest came under sustained attack from TO units, forcing it to surrender. Units from the JNA's Fourth Armoured Corps attempted to move up from Jastrebarsko in Croatia but were beaten back near the border town of Bregana. The Slovenian TO mounted successful attacks on border crossings at Šentilj, Gornja Radgona, Fernetiči and Gorjansko, capturing them and taking a number of JNA troops prisoner. A lengthy engagement between JNA and TO forces took place during the afternoon and evening at Dravograd, and a number of JNA facilities around the country fell to Slovenian forces.
At 2100, the Slovenian Presidency announced a unilateral ceasefire. However, this was rejected by the JNA leadership, which vowed to "take control" and crush Slovenian resistance.

3 July 1991
With a ceasefire now in force, the two sides disengaged. Slovenian forces took control of all of the country's border crossings, and JNA units were allowed to withdraw peacefully to barracks and to cross the border to Croatia.

4–6 July 1991
The Ten-Day War was formally ended with the agreement of the Brioni Accord, signed on the Croatian Brioni Islands. The terms were distinctly favourable to Slovenia; a three-month moratorium on Slovenian independence was agreed — which in practical terms had little real impact — and the Slovenian police and armed forces were recognised as sovereign on their territory.
It was agreed that all Yugoslav military units would leave Slovenia, with the Yugoslav government setting a deadline of the end of October to complete the process. The Slovenian government insisted that the withdrawal should proceed on its terms; the JNA was not allowed to take much of its heavy weaponry and equipment, which was later either deployed locally or sold to other Yugoslav republics. The withdrawal began about ten days later and was completed by 26 October.

7 July 1991 and afterwards
Due to the short duration and low intensity of the war, casualties were low. According to Slovenian estimates, the JNA suffered 44 fatalities and 146 wounded, while the Slovenians had 18 killed and 182 wounded. Twelve foreign nationals were killed in the conflict, principally journalists and Bulgarian truck drivers who had strayed into the line of fire. 4,692 JNA soldiers and 252 federal police officers were captured by the Slovenian side. According to post-war assessments made by the JNA, its material losses amounted to 31 tanks, 22 armoured personnel carriers, 6 helicopters, 6,787 infantry weapons, 87 artillery pieces and 124 air defence weapons damaged, destroyed or confiscated. Property damage was fairly light, due to the scattered and short-term nature of the fighting.

Casualties

Claims of war crimes
The border station at Holmec was the location of an alleged war crime perpetrated by TO forces, filmed by the Austrian public broadcasting station ORF. Video footage shows a small group of JNA soldiers standing or walking slowly with raised hands, holding up a white sheet in an apparent attempt to surrender. Moments later, gunfire is heard and the soldiers fall to the ground. Neither the origin of the gunfire nor its exact effect are clearly visible on the video segment. Slovene officials maintain that the JNA soldiers jumped for cover and were not hit, and that the matter has been thoroughly investigated years ago. However, the incident has sparked renewed public debate after the footage was shown on Serbian TV station B92 in 2006, with many claiming that the soldiers were shot and killed by TO troops and that Slovenia is trying to cover up the affair. ("Serb Official Accuses Slovenia Troops Of War Crimes", 2006-04-08 Associated Press Report, "Slovenia denies Serbian claims of independence war crimes", 2006-04-06 Slovenian News Agency STA Report, "Janša Protests to Koštunica over Statements on Holmec", 2006-04-06 BETA News Agency Report) The fate of the JNA soldiers identified on the footage has been tracked, however, and they were all reported alive 15 years after the conflict.

Holmec Incident
The actions of Slovenia's forces were largely dictated by the military strategy devised some months before and were tightly integrated with an equally detailed media management plan. An international media centre was established prior to the outbreak of conflict with Jelko Kacin designated to act as information minister and Slovenia's public face to the world. The Slovenian government successfully presented the conflict as a case of a "David versus Goliath" struggle between an emerging democracy and an authoritarian communist state, and the columns of Yugoslav tanks inevitably brought to mind the events of the Tiananmen Square protests of 1989 only two years earlier. This won considerable international sympathy and favourable media coverage for the Slovenian cause.
The Slovenians had the advantage of far superior morale, compared to their adversaries in the Yugoslav army. Many of the Yugoslav soldiers apparently did not realise they were taking part in a real military operation, rather than an exercise, until they came under attack. The officer corps was dominated by Serbs and Montenegrins and in many cases ideologically committed to Yugoslav unity. The rank and file troops however were conscripts, who had no interest in fighting Slovenes. Of the soldiers of the 5th Military District, which was in action in Slovenia, in 1990 30% were Albanians, 20% Croats, 10% Bosnian Muslims, 15 to 20% Serbs and Montenegrins, and 8% Slovenes. Serbia was at this point more concerned with the situation in Croatia, even before the war had ended, JNA troops were already repositioning themselves for the imminent war in Croatia.

Strategic aspects of the war
The Ten-Day War had important consequences for all of its participants.
For Slovenia, the war marked the decisive break with Yugoslavia. It was officially recognised by all the European Community member states on 15 January 1992 and joined the United Nations on 22 May, along with the other post-Yugoslav states.
With Croatia as a buffer between it and Serbia, Slovenia was able to maintain its independence and its position as the most stable and prosperous of the former Yugoslav republics and joined the European Union on 1 May 2004.
The war led to a series of major shifts on the Yugoslav side. The JNA rapidly lost virtually all of its Slovenian and Croat personnel, becoming an almost entirely Serbian and Montenegrian force. Its poor performance in Slovenia and later in Croatia discredited its leadership — Kadijević resigned as defence minister in January 1992, and Adžić was forced into medical retirement shortly afterwards. The idea of preserving a unitary Yugoslavia had to be abandoned after the defeat in Slovenia and was replaced by Milošević's conception of "all Serbs in one state" (widely characterised as "Greater Serbia").
Croatia did not become directly involved in the war even though they declared independence on the same day as Slovenia, 25 June 1991. The Croatian government was urged by the European Commission to place a three-month moratorium on the decision of independence; Croatia thereby agreed to freeze its independence declaration for three months, hoping to calm tensions. But even as Croatia began to move towards independence, its territory was still used as the launchpad for JNA incursions into Slovenia. Many Slovenes considered that the Croatians, who were also seeking independence, should have at least tried to obstruct the Yugoslav war effort. This left a degree of distrust which contributed to strained relations between the countries for several years.

Notes

Allcock, John B. et al. Conflict in the Former Yugoslavia. ABC-CLIO, Denver, 1998
Gow, James & Carmichael, Cathie. Slovenia and the Slovenes. C. Hurst, London, 1999
Gow, James. The Serbian Project and its Adversaries. C. Hurst, London, 2003
The War in Croatia and Bosnia-Herzegovina, 1991–1995, ed. Branka Magaš and Ivo Žanić. Frank Cass, London, 2001
Svajncer, Brigadier Janez J. "War for Slovenia 1991", Slovenska vojska, May 2001.