When the Soviet Union began to collapse in the late 1980s, the regional parliament of Nagorno-Karabakh passed a vote to be included in Armenia, which led to ethnic conflict. While the Nagorno-Karabakh region is recognized as Azerbaijani territory internationally, 95% of people in the region — also known as Artsakh — are ethnically Armenian communities, according to the Council for Foreign Relations.
The conflict converted into a war after the Soviet Union collapsed. By 1994, Russia mediated a ceasefire that ended the war and led to Nagorno-Karabakh being an independent region with a government of its own.
Another brief yet intense war took place in 2016 between the two countries, but in 2020, fighting took place again at the Azerbaijan and Nagorno-Karabakh border. Russia facilitated another deal that ended the six-week-long war. By the end of the war in 2020, Azerbaijan gained back the parts of the region it lost in 1994 and Armenia was allocated small parts of Karabakh. The war also ended with the establishment of the Lachin Corridor, which connected Armenia to Nagorno-Karabakh and facilitated a greater flow of goods, services and people.