The Nagorno-Karabakh conflict between Armenia and Azerbaijan, explained

An ethnic Armenian soldier stands guard next to Nagorno-Karabakh's flag atop a hill in the separatist region in Azerbaijan in November 2020. (Sergei Grits/AP)
Placeholder while article actions load

MOSCOW — The conflict between Armenia and Azerbaijan over the contested Nagorno-Karabakh region has simmered for decades. In 2020, the two sides fought a bloody war for territory — one that ended with a fragile Russian-brokered truce.

On Wednesday, tensions flared again in the mountainous enclave, which is located inside Azerbaijan but controlled by ethnic Armenian separatists. Both sides accused each other of breaching the cease-fire and three soldiers, including two from Nagorno-Karabakh and one from Azerbaijan, were killed.

The skirmish prompted international calls to quell the fighting, including from both the Kremlin and U.S. State Department. “We are watching very closely, we are naturally concerned about the situation worsening,” Kremlin spokesperson Dmitry Peskov told reporters Thursday, Reuters reported.

Here’s what you need to know about the fight over Nagorno-Karabakh, the longest-running conflict in the post-Soviet sphere.