Home2018 Treaties and Agreements ...Greece (18-607) – Extension to the Agreement of July 8, 1990 for Mutual Defense Cooperation hide Greece (18-607) – Extension to the Agreement of July 8, 1990 for Mutual Defense Cooperation TIAS Office of Treaty Affairs Defense: Cooperation Agreement extending the Agreement of July 8, 1990, as extended. Exchange of notes at Athens April 30 and June 7, 2018; entered into force June 7, 2018. Download Agreement [828 KB] Tags Defense Greece Treaties