Azerbaijan has arrested former Nagorno-Karabakh leader Ruben Vardanyan as he attempted to flee into Armenia amidst a mass exodus of ethnic Armenians. Azerbaijan recently regained control of Karabakh in a rapid offensive, causing widespread displacement and a humanitarian crisis. The region, internationally recognised as part of Azerbaijan, has a predominantly ethnic Armenian population. Azerbaijan claims it wants peaceful reintegration and guarantees of civic rights, but faces accusations of ethnic cleansing as thousands of Armenians have fled in fear. The EU and Germany have expressed concern and called for international observers, and the UN has called for an investigation into alleged violations of the right to life. Vardanyan's arrest comes as Azerbaijan seeks to prosecute separatist leaders. The situation highlights Russia's diminished role as a security guarantor in the Caucasus region, with competing influences from Turkey, Iran, and the United States. As a result of the crisis, the current leader has said that the enclave will officially cease to exist with effect from 1 January 2024: see