noun
collective security
A political concept where nations agree to respond jointly to aggression against any member. Used in international relations and political science contexts.
国連は集団安全保障の理念に基づいて設立された。
The United Nations was founded on the principle of collective security.
Compound of 集団 (group, collective) + 安全保障 (security). A calque from English 'collective security', likely coined in the context of 20th-century international politics.