It first erupted in the late 1980s, when the Soviet Union still existed but Moscow was no longer able to control the surge of national tensions unleashed by Mikhail Gorbachev’s perestroika reforms.
The roots, however, go deeper—back to the 19th century, when the number of Christian Armenians in the South Caucasus swelled due to migration from Persia and Turkey. Their growing presence often led to clashes with the region’s Muslim Azerbaijani population, especially since Armenians were seen as favoured by the Russian imperial authorities.
Between 1918 and 1920, Nagorno-Karabakh became the main battlefield. Armenians made up an overwhelming majority in the province: 89 percent, according to a 1926 census.
But as the Bolsheviks consolidated power, they placed it inside Soviet Azerbaijan as an autonomous region.
Geography, trade links and infrastructure tied the area more closely to Azerbaijan, and Shusha—a historic Azerbaijani cultural centre—was located there. Still, the decision was driven by Moscow’s classic “divide and rule” logic.
Armenian demands to transfer Nagorno-Karabakh to their republic surfaced as early as the 1960s, and in 1987 a Karabakh Committee was formed to push for it. Azerbaijan rejected the idea outright.
By the time both countries declared independence, they were already at war. A 1994 ceasefire left Armenian forces in control of almost all of Nagorno-Karabakh, plus surrounding lands linking it to Armenia and Iran.
They declared the unrecognized “Republic of Nagorno-Karabakh,” which even Armenia did not formally acknowledge.
That status quo lasted until the autumn of 2020, when Azerbaijan—with Turkish support—launched the Second Karabakh War. In six weeks, it retook large parts of the region, including Shusha. A Russia-brokered ceasefire followed, with Moscow deploying peacekeepers.
In September 2023, Azerbaijan carried out a lightning offensive that restored its control over the rest of Nagorno-Karabakh. Almost the entire Armenian population fled, and soon Russian troops were asked to leave.
With no territory left to contest, the Karabakh conflict effectively ended.
Yerevan had already recognized Azerbaijan’s territorial integrity. Yet the wider Armenia-Azerbaijan dispute remained unresolved: the two states have no diplomatic relations, and their border has been closed for more than three decades, like Armenia’s frontier with Turkey.
Peace would benefit both sides. Armenia could break out of regional isolation, while Azerbaijan would gain a land link to its exclave of Nakhchivan.
But mistrust has been deep, and for years there was no credible mediator. Russia, once the main broker, has lost influence in both capitals. Talks were repeatedly derailed by border skirmishes.
Now, there may be a breakthrough. In March this year, negotiators said they had agreed on the text of a peace deal. On August 8, Armenian Prime Minister Nikol Pashinyan and Azerbaijani President Ilham Aliyev signed a declaration with US President Donald Trump reaffirming their commitment to peace.
At the same summit, their foreign ministers initialed the agreement.
Serious obstacles remain. Baku insists that Armenia amend its constitution, which still references Nagorno-Karabakh in its preamble—language Azerbaijan views as a territorial claim. Yerevan does not rule out the change, but constitutional revisions cannot happen overnight.
Still, violence along the border has subsided, and the two sides have agreed on a long-disputed issue: transit to Nakhchivan.
Instead of an extraterritorial “corridor” that Armenia feared would infringe on its sovereignty, a new road and railway are to operate under a project called TRIPP—the Trump Route for International Peace and Prosperity—managed jointly by Armenia and the United States.
Despite skepticism among analysts, peace between Armenia and Azerbaijan—and potentially between Armenia and Turkey as well—seems closer now than ever before.
Wojciech Górecki
The author is an analyst at the Warsaw-based Centre for Eastern Studies (OSW).