abbreviation for North Atlantic Treaty Organization. An international organization, begun in 1949. Members have pledged to settle disputes among themselves peacefully, and to defend one another against outside aggressors. Member nations include Belgium, Canada, Denmark, Great Britain, Iceland, Italy, Luxembourg, The Netherlands, Norway, Portugal, the United States, Greece, Spain, Turkey and WestGermany and France. —SHSBC Binder 3 Approved Glossary