evidence: This remained in place, for the most part, until the second Nagorno Karabakh war in September 2020. At this time, Azerbaijan launched a major military operation to take back the territory lost to Armenia in the early 1990s. By November, a Russia-led diplomatic effort brought an end to the fighting. Azerbaijan had taken back most, but not all, of the territory it had lost to Armenia, which was decisively defeated on the battlefield. [...] The border delineation process is also affected by the status of four remaining enclaves: the Armenian enclave of Artsvashen inside Azerbaijan, and the Azerbaijani enclaves of Barkhudarly, Yukhari Askipara, and Karki inside Armenia. [...] Finally, there is the issue of perceived territorial claims in neighboring countries as referenced in Armenia’s Constitution. The preamble of the current version of the document references the "pan-national aspirations" of ethnic Armenians. It also specifically cites Armenia’s 1990 Declaration of Independence from the Soviet Union that called for the unification of Armenia and ethnic Armenians living in Azerbaijan’s Karabakh region. Understandably, Azerbaijan has never liked this wording and wants it changed.