Isolationism is the belief — and the political habit that grows from it — that your country should keep out of other countries' fights, deals, and problems and look after itself. A government that follows it may refuse close ties, stay out of wars abroad, and try to limit how much it is pulled into the rest of the world's business. You meet the word in history and in news about foreign policy, not as a word for a shy person. A quiet student is not practising isolationism. Though actually, people stretch it: almost any we should stay out of this move may get the label, even when the country is still trading, talking, and taking sides in smaller ways. The tidy picture is a country that simply turns its back; real policy is usually messier than that, and critics and supporters rarely mean quite the same thing by the word.