From the Introduction: "In autumn 2020, a six-week war fundamentally reshaped the dynamics of a decades-old conflict between Azerbaijan and Armenia over the disputed region of Nagorno-Karabakh (or Mountainous Karabakh, also known in Armenian as Artsakh) and surrounding territories internationally recognized as part of Azerbaijan. [...] This report focuses on the Azerbaijan-Armenia conflict, the autumn 2020 war, and related U.S. policy. It first provides brief historical background and then discusses the post-1994 conflict resolution process and the relationships of Azerbaijan and Armenia with regional powers Russia and Turkey. In addition, the report provides analysis of the autumn 2020 war, the November 2020 cease-fire agreement, and the war's domestic impact in Armenia and Azerbaijan. The report then discusses U.S. responses to the war, longer-term U.S. policy toward the conflict, and the role of Congress."
CRS Report for Congress, R46651
Congressional Research Service: https://crsreports.congress.gov/