Azerbaijani military operation, 19–20 September 2023 §

Background

By September 2023 the residual Republic of Artsakh / NKR consisted of approximately 3,000 km² of mountain territory around Stepanakert, home to roughly 120,000 Armenians under the increasingly nominal protection of the Russian peacekeeping contingent and the increasingly real pressure of the Lachin blockade. The NKR Defence Army numbered perhaps 7,000–10,000 personnel, organised in light-infantry battalions with limited armour and effectively no air defence; their supply lines had been severed for nine months; the population was malnourished and exhausted.

The Russian peacekeepers' mandate ran until November 2025, but Russia's strategic position had been transformed by the war in Ukraine. The 15th Motor Rifle Brigade had been substantially drawn down, the relationship between the Aliyev and Putin administrations had been recalibrated through Azerbaijani neutral signalling on Ukraine, and Yerevan's relationship with Moscow had reached its lowest point since independence. The Russian peacekeepers, in ICG's assessment, had become "spectators."

The Armenian government under Nikol Pashinyan had effectively conceded the legal architecture of the Karabakh question at the Prague summit of October 2022 by accepting Soviet-era boundaries as the basis for delimitation. The remaining question was the welfare of the Karabakh Armenian population, on which Yerevan had little leverage and Baku no inclination to negotiate.

Azerbaijan's military preparation through summer 2023 was open. Mobilisation along the line of contact was visible through commercial satellite imagery. Bayraktar drone activity increased; artillery emplacements were prepared. The trigger came on 19 September: Azerbaijan announced that four soldiers had been killed by mines in a non-public road inside Karabakh and declared the launch of "anti-terrorist measures" against the NKR Defence Army.

The event

The offensive began at 13:00 on 19 September 2023 with multi-axis artillery and missile preparation followed by ground assault. Azerbaijani forces struck simultaneously across the entire residual front: the Askeran sector north of Stepanakert, the Martuni sector to the east, and the Martakert sector to the north. Armenian positions were systematically broken; communications were severed by electronic warfare; multiple armoured units were destroyed by drone strikes.

Civilian casualties in Stepanakert and the surrounding villages were caused by artillery fire on populated areas, although Azerbaijan asserted that only military targets were struck contested. Civilian casualty figures from Armenian-government and NKR sources cite at least 200 dead, including 25 children; Azerbaijan acknowledged five Azerbaijani civilian deaths and seven military.

The NKR Defence Army was unable to mount coherent resistance. Within twelve hours, multiple Armenian brigade commanders had requested ceasefire; by the morning of 20 September, the NKR military and political leadership had agreed to the disarmament and dissolution of NKR forces. The ceasefire was negotiated through the Russian peacekeeping command and announced at 13:00 on 20 September, exactly twenty-four hours after the operation began.

The terms of the ceasefire were political capitulation: complete disarmament of NKR military formations under Azerbaijani supervision, integration of Karabakh Armenians "as ordinary citizens" of Azerbaijan, and the immediate beginning of negotiations on the future of the population. Azerbaijani forces did not enter the residual Armenian-populated areas in the first days; they took up positions on the perimeter.

Aftermath

In the days following the ceasefire, Azerbaijani President Aliyev gave a televised address from a refurbished government building in Khankendi (the Azerbaijani name for Stepanakert), framing the operation as the long-awaited restoration of constitutional order. The remaining NKR political leadership, including President Samvel Shahramanyan, signed agreements over the following days dissolving the political institutions of NKR. On 28 September, Shahramanyan signed the decree formally dissolving the Republic of Artsakh effective 1 January 2024.

Several NKR leaders, including former state ministers Ruben Vardanyan, David Babayan, Davit Manukyan and Davit Ishkhanyan, and former president Bako Sahakyan, were detained as they attempted to leave through the Lachin corridor and have been held in pre-trial detention in Baku since. Their trials, opening in early 2025, have been criticised by international observers including the EU and the Council of Europe Commissioner for Human Rights as failing minimum fair-trial standards contested.

But the principal aftermath was the exodus. From 24 September the Lachin Corridor was opened for Armenian movement out of NKR; over the following ten days, 100,617 forcibly displaced persons were registered by UNHCR crossing into Armenia. By the end of October, the residual Armenian population of NKR was effectively zero. By September 2024, only 14 ethnic Armenians remained in the territory.

Memory and politics

The 24-hour operation has been characterised in widely divergent terms. The EU Parliament resolution of 5 October 2023 used the language of "ethnic cleansing." The Ocampo opinion characterised the broader course of conduct as genocide. The Armenian government's legal position, advanced before the ICJ in November 2023 (the November 2023 order) treats the operation as the culmination of an unlawful pattern. The Azerbaijani government characterises the operation as a legitimate domestic counter-terrorist action and the resulting displacement as voluntary emigration contested.

In the academic literature, the working consensus, articulated by de Waal in the 2023 revised edition of Black Garden and Broers in subsequent commentary, treats the operation as the executory phase of a multi-stage process of ethnic removal whose previous stages were the blockade and the 2020 war. Whether the conduct in aggregate satisfies the legal definition of genocide remains a question for the ongoing ICJ proceedings; the political characterisation as ethnic cleansing is broadly accepted editorial.