Related Clues:

• Defense grp.
• Treaty grp.
• The U.S. is in it
• Defense grp. since 1949
• OSS successor
• Alliance acronym
• FBI ally
• Group with hdqrs. in Belgium
• Former OSS
• It's known for its intelligence
• 1949 defense org.
• Cold war winner
• Bug group?: Abbr.
• Jack Ryan's employer (Abbr.)
• OSS follower