Home2010 Treaties and Agreements ...Greece (10-521) – Agreement Extending the July 8, 1990 Mutual Defense Cooperation Agreement hide Greece (10-521) – Agreement Extending the July 8, 1990 Mutual Defense Cooperation Agreement TIAS Office of Treaty Affairs May 21, 2010 Defense Agreement effected by exchange of notes at Athens April 14 and May 21, 2010; entered into force May 21, 2010. Agreement Effected by exchange of notes at Athens August 1 and October 11, 2011; entered into force October 11, 2011. Download attachment [330 KB] Tags Defense Greece Treaties