On 12 March 1999, the Czech Republic, Hungary, and Poland joined NATO; Bulgaria, Estonia, Latvia, Lithuania, Romania, and Slovakia joined in March 2004; Albania joined on 1 April 2009.
On 12 March 1999 , the Czech Republic , Hungary , and Poland joined NATO ; Bulgaria , Estonia , Latvia , Lithuania , Romania , and Slovakia joined in March 2004 ; Albania joined on 1 April 2009 .
In which year did Slovakia join NATO?
In which year did Slovakia join NATO ?
2004
2004