A ceasefire signed in 1994 provided for two decades of relative stability, which significantly deteriorated along with Azerbaijan's increasing frustration with the status quo, at odds with Armenia's efforts to cement it. A four-day escalation in April 2016 became the deadliest ceasefire violation to date. Since then, the possibility of resumed major hostilities has greatly increased.
With Perestroika and the dissolution of the Soviet Union in 1989, ethnic tensions between Armenians and Azerbaijanis increased in the Nagorno-Karabakh region.
As of 2017, public opinion on both sides has been noted as "increasingly entrenched, bellicose and uncompromising". In this context, mutual concessions that might lower tensions in the longer term could in the shorter run threaten internal stability and the survival of ruling elites, hence leaving little incentive for compromise.
The enclave's parliament had voted in favor of uniting with Armenia. A a referendum, boycotted by the Azerbaijani population of Nagorno-Karabakh, was held, whereby most of the voters voted in favor of independence. The demand to unify with Armenia, which began anew in 1988, began in a relatively peaceful manner. As the Soviet Union's dissolution neared, the tensions gradually grew into an increasingly violent conflict between ethnic Armenians and ethnic Azerbaijanis. Both sides made claims of ethnic cleansing and pogroms conducted by the other.
Inter-ethnic clashes between the two broke out shortly after the parliament of the Nagorno-Karabakh Autonomous Oblast (NKAO) in Azerbaijan voted to unify the region with Armenia on 20 February 1988. The circumstances of the dissolution of the Soviet Union facilitated an Armenian separatist movement in Soviet Azerbaijan. The declaration of secession from Azerbaijan was the final result of a territorial conflict regarding the land. As Azerbaijan declared its independence from the Soviet Union and removed the powers held by the enclave's government, the Armenian majority voted to secede from Azerbaijan. In the process they proclaimed the unrecognizedRepublic of Nagorno-Karabakh.
Full-scale fighting erupted in the late winter of 1992. International mediation by several groups, including the Organization for Security and Co-operation in Europe (OSCE), failed to bring resolution. In the spring of 1993, Armenian forces captured territory outside the enclave itself, threatening to catalyze the involvement of other countries in the region. By the end of the war in 1994, the Armenians were in full control of most of the enclave and also held and currently control approximately 9% of Azerbaijan's territory outside the enclave. As many as 230,000 Armenians from Azerbaijan and 800,000 Azerbaijanis from Armenia and Karabakh have been displaced as a result of the conflict. A Russian-brokered ceasefire was signed in May 1994 and peace talks, mediated by the OSCE Minsk Group, have been held ever since by Armenia and Azerbaijan.
Some clashes occurred in the years following the 1994 ceasefire.
Border clashes (1994–2016)
The situation in the area after the 1994 ceasefire
Armenian sources accused Azerbaijan of trying to take advantage of ongoing unrest in Armenia. Azerbaijani sources blamed Armenia, claiming that the Armenian government was trying to divert attention from internal tensions in Armenia.
In late April 2011, border clashes left three Nagorno-Karabakh soldiers dead, while on 5 October, two Azerbaijani and one Armenian soldier were killed. In all during the year, 10 Armenian soldiers were killed.
The following year, border clashes between the armed forces of Armenia and Azerbaijan took place from late April through early June. The clashes resulted in the deaths of five Azerbaijani and four Armenian soldiers. In all during 2012, 19 Azerbaijani and 14 Armenian soldiers were killed. Another report put the number of Azerbaijani dead at 20.
Throughout 2013, 12 Azerbaijani and 7 Armenian soldiers were killed in border clashes.
In 2014, several border clashes erupted that had resulted in 16 fatalities on both sides by 20 June.
On 2 August, Azerbaijani authorities announced that eight of their soldiers had been killed in three days of clashes with NKO forces, the biggest single death toll for the country's military since the 1994 war. NKO denied any casualties on their side, while saying the Azerbaijanis had suffered 14 dead and many more injured. Local officials in Nagorno-Karabakh reported at least two Armenian military deaths in what was the largest incident in the area since 2008. Five more Azerbaijani troops were killed the following night, bringing the death toll from the August clashes to at least 15. The violence prompted Russia to issue a strong statement, warning both sides not to escalate the situation further.
By August 5, 2014 the fighting that started on 27 July had left 14 Azerbaijani and 5 Armenian soldiers dead. Overall, 27 Azerbaijani soldiers had died since the start of the year in border clashes.
In a separate incident in July 2014, the NKR Defense Army announced that troops had killed one and arrested two members of an Azerbaijani subversive group that had penetrated the contact line. In addition to spying on Armenian troop movements and military installations and civilian settlements in Karvachar (Kelbajar), the team was charged with the murder of Smbat Tsakanyan, a seventeen-year-old Armenian boy and resident of the village of Jumen. Both surviving members of the group were sentenced to life in prison by an Armenian court. In July 2015, video footage recorded by the team was released to the public and aired on Armenian state television.
On November 12, 2014, the Azerbaijani armed forces shot down a Nagorno-Karabakh Defense Army Mil Mi-24 helicopter over Karabakh's Agdam district. Three servicemen were killed in the incident. Armenia's Defense Ministry stated the aircraft was unarmed and called its downing an "unprecedented provocation". Azerbaijani authorities claimed the helicopter was "trying to attack" Azerbaijani army positions. Armenian authorities stated that Azerbaijan will face "grave consequences". With the crash, 2014 became the deadliest year for Armenian forces since the 1994 ceasefire agreement, with 27 soldiers killed in addition to 34 fatalities on the Azerbaijani side. Six Armenian civilians also died in 2014, while by the end of the year the number of Azerbaijanis killed rose to 39 (37 soldiers and 2 civilians).
2015 sporadic fighting
In 2015, 42 Armenian soldiers and 5 civilians were killed as border clashes continued. In addition, at least 64 Azerbaijani soldiers also died.
Over the years, Azerbaijan had been growing impatient with the status quo. In this regard, propelled by oil and gas windfall, the country embarked in a military build-up. In 2015 alone, Baku spent $3bn on its military, more than Armenia's entire national budget.
Throughout January and February 2016, four Armenian and four Azerbaijani soldiers were killed in fighting at the Nagorno-Karabakh border. The first casualty of 2016 was a Nagorno-Karabakh soldier Aramayis Voskanian, who was killed by Azerbaijani sniper fire while serving in the eastern direction of the Line of Contact. In mid-February, Hakob Hambartsumyan, an Armenian herdsman from Vazgenashen, was killed by an Azerbaijani sniper. In March, two Azerbaijani and one Armenian soldier were killed in clashes along the border between Azerbaijan and Armenia.
Between 1 and 5 April 2016, heavy fighting along the Nagorno-Karabakh frontline left 88 Armenian and 31–92 Azerbaijani soldiers dead. One Armenian and three Azerbaijani soldiers were also missing. In addition, 10 civilians (six Azerbaijani and four Armenian) were also killed. During the clashes, an Azerbaijani military helicopter, 13 unmanned drones were shot down and an Azerbaijani tank was destroyed.
Renewed border clashes (2016–present)
Between 8 and 17 May 2016, sporadic fighting left 14 Armenian and three Azerbaijani soldiers dead, as well as one Azerbaijani civilian.
On 5 October 2016, Armenian artillery shelled Azerbaijani positions on the line of contact with one Azerbaijani soldier being killed. One Armenian soldier was killed on 11 October 2016 in a skirmish on the line of contact. On 15 November, an Azerbaijani soldier was killed on the line of contact. On 27 November, Azerbaijani forces reported shooting down an Armenian drone which had crossed the line of contact.
A Nagorno-Karabakh soldier was killed in action with Azerbaijiani forces on 6 February 2017. On 8 February 2017, one Nagorno-Karabakh soldier was killed and another wounded in a firefight with Azerbajiani troops along the line of contact. On 24 February 2017, Azerbaijani forces shelled the Armenian positions near the village of Talish with artillery. The next day a large firefight broke out with Azerbajiani forces approaching Armenian lines in the same area, 5 Azerbaijani soldiers were killed in the ensuing engagement.
On 15 May 2017, a Karabakh Osa air defense system was damaged or destroyed by a guided missile launched by Azerbaijani forces. On 20 May 2017, an Armenian soldier was killed in a firefight with Azeri troops, the Azerbaijani military utilized anti-tank grenades and 60mm mortar fire in the action. On 26 May 2017, a Nagorno-Karabakh soldier was killed in a skirmish with Azerbajiani forces involving mortars and grenade launches. On 16 June 2017 three Nagorno-Karabakh soldiers were killed by Azeri forces. On 22 June 2017 four Azeri soldiers were killed by Nagorno-Karakakh soldiers. On July 4 an Azeri woman and her two-year-old grandchild were killed as a result of shelling by Armenian forces. On 10 July 2017 a Nagorno-Karabakh soldier was killed in shelling by the Azerbaijani forces. On 25 July 2017, Azerbaijan claimed that one of its soldiers was wounded by a munition dropped from an Armenian UCAV. On 31 August 2017, Azerbaijani military positions were fired at and shelled at from Armenian military positions. The Armenian military were using large-caliber machine guns.
A Nagorno-Karabakh soldier was killed by an Azerbaijani sniper near the line of contact on 7 January 2018.
A Nagorno-Karabakh soldier was killed by Azerbaijani fire on 7 February 2018.
Three civilian volunteers were killed in a demining operation in Nagorno-Karabakh on 29 March 2018.
A Nagorno-Karabakh soldier was killed by Azerbaijani fire on 9 April 2018. A Nagorno-Karabakh soldier was killed in a firefight with Azeri forces on 10 June 2018. In September 2018 a soldier of the Armenian Army was killed by Azeri gunfire whilst serving at a border post. In the same month, two Nagorno-Karabakh soldiers were killed by the Azeri army.
Although no exact casualty figures exist, by 2009, as many as 3,000 people, mostly soldiers, had been killed, according to most observers.
In 2008, the fighting became more intense and frequent. With 72 deaths recorded throughout the year, 2014 became the bloodiest since the war ended. According to the Union of Relatives of the Artsakh War Missing in Action Soldiers, as of 2014, 239 Karabakhi soldiers remain officially listed as unaccounted for.Between 1 and 5 April 2016, heavy fighting along the Nagorno-Karabakh frontline left 27 Armenian and 28 Azerbaijani soldiers dead. 26 Armenian soldiers were also missing. In addition, six civilians (four Armenian and two Azerbaijani) were killed.
^Özden Zeynep Oktav (2013). Turkey in the 21st Century: Quest for a New Foreign Policy. Ashgate Publishing. p. 126. ISBN9781409476559. ...Turkey's support for Azerbaijan in the conflict over Nagorno-Karabakh...
^Flanagan, Stephen J.; Brannen, Samuel (2008). Turkey's Shifting Dynamics: Implications for U.S.-Turkey Relations. Washington, DC: Center for Strategic and International Studies. p. 17. ISBN9780892065363. Turkey's border with Armenia has remained sealed since 1994, due to Turkish support for Azerbaijan in the Nagorno-Karabakh conflict.
^Hunter, Shireen (2004). "Russia and the Transcaucasus: The Impact of the Islamic Factor". Islam in Russia: The Politics of Identity and Security. M.E. Sharpe. p. 349. Aliev thanked Pakistan for its support in the Karabakh conflict.
^Four UN Security Council resolutions, passed in 1993, called for withdrawal of Armenian forces from the regions falling outside the borders of the former NKAO.
^Using numbers provided by journalist Thomas de Waal for the area of each rayon, as well as the area of the Nagorno-Karabakh Oblast and the total area of Azerbaijan are (in km2):
totaling 7,709 km2 (2,976 sq mi) or 8.9%: De Waal. Black Garden, p. 286.