About Bucharest Nine?

• The “Bucharest Nine” is a group of nine NATO countries in Eastern Europe that became part of the US-led military alliance after the end of the Cold War.
• The Bucharest Nine or Bucharest Format, often abbreviated as the B9, was founded on November 4, 2015, and takes its name from Bucharest, the capital of Romania.

Composition

• The B9 are, apart from Romania and Poland, Hungary, Bulgaria, the Czech Republic, Slovakia, and the three Baltic republics of Estonia, Latvia, and Lithuania.
• All nine countries were once closely associated with the now dissolved Soviet Union, but later chose the path of democracy.
• Romania, Poland, Hungary, and Bulgaria are former signatories of the now dissolved Warsaw Pact military alliance led by the Soviet Union. (The other Warsaw Pact countries were the erstwhile Czechoslovakia and East Germany, and Albania.) Estonia, Latvia, and Lithuania were part of the former Union of Soviet Socialist Republics (USSR).
• All members of the B9 are part of the European Union (EU) and North Atlantic Treaty Organization (NATO).

Reference:

1. https://indianexpress.com/article/explained/everyday-explainers/bucharest-nine-nato-countries-eastern-europe-explained-7836360/