Casus belli
Casus belli, a Latin term describing a situation said to justify a state in initiating war. The United Nations charter provides that warlike measures are permissible only if authorized by the Security Council or the general assembly or if necessary for "individual or collective self-defense" against "armed attack."
This article was most recently revised and updated by Michael Ray.
Citation Information
Article Title:
Casus belli
Website Name:
Encyclopaedia Britannica
Publisher:
Encyclopaedia Britannica, Inc.
Date Published:
31 October 2026
Access Date:
November 13, 2026