Post-Soviet states
The three Baltic states – Estonia, Latvia, and Lithuania – were the first to declare their independence from the USSR, between March and May 1990. They claimed continuity from the original states which existed before  the annexation by the Soviet Union in 1940. The remaining 12 republics all left after. All 12 of these republics joined the Commonwealth of Independent States (CIS) and most of the 12 joining the Collective Security Treaty Organization (CSTO). However, the Baltic states focused on European Union (EU) and NATO membership. EU officials have made clear the importance of Association Agreements between the EU and post-Soviet states.