Armenia vs Azerbaijan: Nagorno-Karabakh Conflict

The Nagorno-Karabakh conflict[f] is an ethnic and territorial conflict between Armenia and Azerbaijan over the disputed region of Nagorno-Karabakh and seven surrounding districts, which are de facto controlled by the self-declared Republic of Artsakh, but are internationally recognized as de jure part of Azerbaijan. The conflict has its origins in the early 20th century. Under the Soviet Union, Joseph Stalin decided to make the Nagorno-Karabakh region an autonomous oblast of Soviet Azerbaijan. The present conflict began in 1988, when the Karabakh Armenians demanded that Karabakh be transferred from Soviet Azerbaijan to Soviet Armenia. The conflict escalated into a full-scale war in the early 1990s.

A ceasefire signed in 1994 provided for two decades of relative stability, which significantly deteriorated along with Azerbaijan's increasing frustration with the status quo, at odds with Armenia's efforts to cement it. A four-day escalation in April 2016 became the deadliest ceasefire violation until the 2020 crisis.