Question

which u.s. policy weakened the league of nations?
☐ isolationism
☐ imperialism
☐ interventionism
☐ militarism

Explanation:

The League of Nations aimed for collective security. U.S. isolationism meant the U.S. refused to join the League, reducing its global support, authority, and ability to enforce decisions, thus weakening it. Imperialism focuses on territorial expansion, interventionism on foreign involvement (but U.S. didn't intervene via the League), and militarism on military buildup—none match as directly as isolationism.

Answer:

A. Isolationism