The term 'Treaty Group' refers to three different international alliances: the Allies (6 letters), NATO (4 letters), and SEATO (5 letters). The Allies were a coalition of countries that fought against the Axis powers in World War II. NATO, or the North Atlantic Treaty Organization, is an intergovernmental military alliance between 30 North American and European countries. SEATO, or the Southeast Asia Treaty Organization, was a Cold War-era mutual defense treaty between the United States, Australia, France, New Zealand, Pakistan, Thailand, and the United Kingdom.