After the fall of the Communists in 1989, Poland joined NATO in 1999 & this economic group of nations on May 1, 2004
[DOC] [TLE] 2004 enlargement of the European Union - Wikipedia [PAR] The 2004 enlargement of the European Union was the largest single expansion 
of the European Union (EU), in terms of territory, number of states, and 
population to date; however, it was not the largest in terms of gross domestic 
product.