SEATO was a club of countries that promised to send military help if there was fighting in Southeast Asia or the nearby Pacific. The letters stand for Southeast Asia Treaty Organization — a long written promise between governments, not a place. It began in 1954, in the tense years after World War II, when some countries were afraid another kind of power would spread through Asia. The members were Australia, Britain, France, New Zealand, the Philippines, Thailand, and the United States. Though actually, Pakistan was in it too; tidy lists often leave that out. And though the name says Southeast Asia, only two members (the Philippines and Thailand) really sit there — the rest were bigger countries joining from outside. People often set it beside NATO, the similar club in Europe, but SEATO was always weaker and less sure of itself. It slowly fell apart after the war in Vietnam and closed in 1977. You meet the word in history class now, not in the news. People usually say it as a word, SEE-toh, not letter by letter.

東南亞公約組織（SEATO）。冷戰時的軍事同盟，1977 年已解散。台灣跟「北約」一樣用「公約組織」；中國大陸較常寫「條約組織」。