A large hidden hydraulic system mapped around the Urartian fortress of Argisht

Azerbaijan launched a military offensive on September 19, 2023; local Armenian authorities agreed to a ceasefire the following morning. By the end of September, more than 100,000 ethnic Armenians, roughly 99 percent of the region’s population, had fled through the Lachin Corridor into Armenia. Shusha, the city overlooking the regional capital Stepanakert from the ridge above, had already fallen during the 44-day war in 2020, strengthening Azerbaijan’s hand before the 2023 offensive. Artsakh’s de facto president Samvel Shahramanyan issued a decree on September 28, 2023, ordering all state institutions dissolved by January 1, 2024. Azerbaijan administers the entire territory directly today.

The Conflict Emerged During The Soviet Collapse

During the Soviet period, Moscow organised Nagorno-Karabakh as the Nagorno-Karabakh Autonomous Oblast within the Azerbaijan Soviet Socialist Republic, even though ethnic Armenians made up most of the local population. Political tensions intensified on February 20, 1988, when the regional Soviet voted 110 to 17 to request the transfer of the territory out of Azerbaijan and into Soviet Armenia. The vote triggered intercommunal violence across both republics, including the Sumgait pogrom of February 27 to March 1, 1988, in which dozens of ethnic Armenians were killed.

Violence escalated further after Armenia and Azerbaijan became independent states in late 1991. Armenian-backed forces gained control over most of Nagorno-Karabakh and seven surrounding Azerbaijani districts during the war that followed. Hundreds of thousands of people fled their homes during the fighting: roughly 724,000 Azerbaijanis were displaced from Armenia, Nagorno-Karabakh, and the seven adjacent districts, while several hundred thousand ethnic Armenians left Azerbaijani cities. Total deaths from the First Nagorno-Karabakh War (1988-1994) are estimated at around 30,000 on both sides combined.

Russia brokered the ceasefire that ended the war. The Bishkek Protocol was signed by parliamentary representatives of Armenia, Azerbaijan, and Nagorno-Karabakh on May 5, 1994, and the ceasefire took effect on May 12, 1994. The agreement froze the front lines but did not resolve the region’s political status. Armenian-backed authorities continued governing the territory as the self-proclaimed Nagorno-Karabakh Republic, later also called the Republic of Artsakh, although no United Nations member state, including Armenia itself, formally recognised it as independent.

For more than two decades, negotiations produced little progress. The Organization for Security and Co-operation in Europe (OSCE) Minsk Group, co-chaired by Russia, France, and the United States, led most international mediation efforts, while periodic clashes continued along the line of contact, including the Four-Day War of April 2016.

The 2020 War Reshaped The Region

Large-scale fighting resumed on September 27, 2020. Azerbaijan launched a coordinated offensive that drew heavily on Bayraktar TB2 and Harop drones for surveillance and strikes, supported by artillery and armoured units. Turkey openly backed Azerbaijan; Russia maintained ties with both sides and chose not to invoke the Collective Security Treaty Organization commitments that Armenia argued should have applied.

The 44-day war significantly changed control of the region. Azerbaijani forces recaptured the seven surrounding districts (Agdam, Fuzuli, Jabrayil, Zangilan, Gubadli, Khojavend, and Kalbajar) and on November 8, 2020, took the city of Shusha (Shushi in Armenian) after a week of close-quarters fighting. The city overlooks Stepanakert from a clifftop ridge and was strategically decisive: its capture made the Armenian position in the regional capital untenable.

Russia brokered the trilateral ceasefire agreement, signed by Ilham Aliyev, Nikol Pashinyan, and Vladimir Putin on November 9, 2020, with the ceasefire taking effect at midnight Moscow time on November 10. Under the agreement, Armenia transferred additional territories to Azerbaijan; roughly 1,960 Russian peacekeepers deployed to the remaining Armenian-administered area and the Lachin Corridor; and the parties committed to a future transit route connecting Azerbaijan with its Nakhchivan exclave through southern Armenia. In all, the Armenian side lost roughly 75 percent of the territories in and around Nagorno-Karabakh that it had controlled before the war, including Shusha, Hadrut, and the seven surrounding districts.

The Lachin Corridor Crisis And The 2023 Offensive

Conditions inside Nagorno-Karabakh deteriorated sharply through 2022 and 2023. On December 12, 2022, Azerbaijani demonstrators (described by Armenia and several Western governments as state-backed) blockaded the Lachin Corridor, the only road link between Nagorno-Karabakh and Armenia. On February 22, 2023, the International Court of Justice ordered Azerbaijan, by a vote of 13 to 2, to ensure unimpeded movement along the corridor. On April 23, 2023, Azerbaijan instead opened a permanent checkpoint on the route, which it framed as a customs and security measure but which Armenian officials and the Lemkin Institute for Genocide Prevention argued was a continuation of the blockade.

Diplomatic efforts involving Russia, the European Union, and the United States did not produce a long-term settlement, and food, medicine, and fuel shortages worsened throughout 2023. On September 19, 2023, Azerbaijan launched what it called an “anti-terror operation” against Armenian armed formations remaining in Nagorno-Karabakh. Azerbaijani forces advanced rapidly through high ground and key road junctions; within about 24 hours, local Armenian authorities accepted a Russian-mediated ceasefire on September 20. Casualty figures reported by the two sides were 192 Azerbaijani military personnel killed and 511 wounded, against more than 200 Armenian killed and more than 400 wounded.

The offensive ended the separatist administration’s ability to govern the territory. A mass exodus through the Lachin Corridor began within days. The Berkadzor fuel depot explosion on September 25, 2023, killed at least 218 evacuees who had queued for fuel before the long drive to Armenia; another roughly 70 people died on the road during the exodus itself. By October 3, 2023, more than 100,617 ethnic Armenians had crossed into Armenia, roughly 99 percent of the pre-offensive population of Nagorno-Karabakh. On September 28, 2023, Artsakh president Samvel Shahramanyan signed a decree formally dissolving all state institutions of the self-proclaimed republic by January 1, 2024.

Nagorno-Karabakh In 2026

Azerbaijan controls the entirety of Nagorno-Karabakh and administers the territory directly. Reconstruction has progressed across the seven surrounding districts and within Nagorno-Karabakh proper, with substantial public investment in roads, housing, an international airport at Fuzuli (opened October 2021), and the planned return of Azerbaijani families displaced in the 1990s. Russia confirmed in April 2024 that it was withdrawing the peacekeeping contingent deployed under the 2020 agreement; the withdrawal was completed in mid-2024, roughly a year and a half before the original five-year mandate would have ended in November 2025.

The status of negotiations between Yerevan and Baku has moved further than at any previous point. On March 13, 2025, the two foreign ministries jointly announced that they had finalised the text of an Agreement on Peace and the Establishment of Interstate Relations. On August 8, 2025, Armenian Prime Minister Nikol Pashinyan and Azerbaijani President Ilham Aliyev initialled the agreement at the White House under the mediation of US President Donald Trump, and the three leaders signed a separate Joint Declaration on Future Relations the same day. The agreement commits the two parties to establish diplomatic relations, delimit their shared border, and develop a transit corridor through southern Armenia connecting Azerbaijan with its Nakhchivan exclave; the corridor has been branded the Trump Route for International Peace and Prosperity (TRIPP), with the United States granted exclusive 99-year development rights.

The agreement has been initialled but not yet signed or ratified by either parliament. Azerbaijan has stated that it will not sign until Armenia removes from its constitution language that Baku interprets as a territorial claim; Armenia has begun preparing the constitutional amendments, with a national referendum likely required in 2027. Armenian parliamentary elections are scheduled for June 7, 2026, with constitutional changes and the peace process both shaped by the result. Many of the roughly 100,000 ethnic Armenians displaced from Nagorno-Karabakh in 2023 remain in Armenia and have not returned.

Nagorno-Karabakh occupies a small section of the South Caucasus, but it has shaped the region’s politics for almost four decades. Soviet administrative borders, mountainous geography, ethnic demographics, and successive military realities all contributed to one of the longest-running territorial disputes to emerge from the collapse of the Soviet Union. Whether the August 2025 agreement ultimately ends that dispute or only the most recent phase of it depends largely on what happens in Armenian domestic politics and in the eventual ratification process.