[ahy-suh-ley-shuh-niz-uh
m, is-uh-] 
| the policy or doctrine of isolating one's country from the affairs of other nations by declining to enter into alliances, foreign economic commitments, international agreements, etc., seeking to devote the entire efforts of one's country to its own advancement and remain at peace by avoiding foreign entanglements and responsibilities. |
| i·so·la·tion·ism (ī'sə-lā'shə-nĭz'əm) n. A national policy of abstaining from political or economic relations with other countries. i'so·la'tion·ist n. |
The doctrine that a nation should stay out of the disputes and affairs of other nations. The United States practiced a policy of isolationism until World War I and did not pursue an active international policy until after World War II. (See “entangling alliances with none.”)