Isolationism
Etymology
From Latin insula, “island,” which gave “isolate” — literally “made into an island.” The -ism took hold in early-twentieth-century American debate, especially over whether to enter European wars, to name the preference for standing apart. The imagery is apt: the isolationist wants the country to behave, in effect, like an island unto itself.
noun · /eye-suh-LAY-shuh-niz-um/
A foreign-policy stance favoring minimal involvement in other countries’ affairs, alliances, and conflicts.
What it names
The impulse to keep a country out of foreign entanglements — the counterweight in every debate over whether to intervene abroad.
Example
After the long war, a wave of isolationism made voters wary of any new commitment overseas.
Related idea
Protectionism is about walling off the economy from foreign goods; isolationism is about walling off foreign policy from foreign entanglements, and the two need not go together.