Armenia-Azerbaijan: tensions existed for years over the break-away Nagorno-Karabakh region and the Armenian military occupation of surrounding lands in Azerbaijan; Azerbaijan seized part of the enclave during six weeks of fighting in 2020 and the remainder in a short conflict in September 2023; in October 2023, Baku and Yerevan began preliminary discussions on a peace treaty, the demarcation of borders, and full normalization of relations; nevertheless, concerns persist in Armenia that Azerbaijan could invade in order to force the establishment of a transit corridor to the exclave of Naxicvan (Nakhichevan)

Azerbaijan-Georgia: a joint boundary commission agrees on most of the alignment, leaving only small areas at certain crossing points in dispute; consequently, the two states have yet to agree on a delimitation or demarcation of their common boundary; one area of contention is where the international boundary should run through the 6th-13th Century David-Gareja monastery complex

Azerbaijan-Iran: in recent years, tensions between Azerbajian and Iran have risen in part because of warming ties between Azerbaijan and Israel, and Baku's claims that Tehran has backed Armenia over the disputed Nagorno-Karabakh enclave

Azerbaijan-Russia: Russia has complained of cross-border smuggling

Azerbaijan-Turkey: none identified; as of 2023, Turkey and Armenia were discussing normalizing relations

Caspian Sea (Maritime Boundary): Azerbaijan, Kazakhstan, and Russia ratified the Caspian seabed delimitation treaties based on equidistance, while Iran continues to insist on a one-fifth slice of the sea; bilateral talks continue with Turkmenistan on dividing the seabed and contested oilfields in the middle of the Caspian

local border forces struggle to control the illegal transit of goods and people across the porous, undemarcated Armenian, Azerbaijani, and Georgian borders