If you refer to isolationism, you are referring to a country's policy of avoiding close relationships with other countries and of not taking sides in disputes between other countries.
例句
...the perils of isolationism.孤立主义的危险
英汉词典释义
n.
孤立主义
Isolationism is a strictly national policy.隔离主义是一顶严格的国家政策。
英英词典释义
Noun
1. a policy of nonparticipation in international economic and political relations