casus belli

noun ca·sus bel·li \ ˈkä-səs-ˈbe-ˌlē , ˈkā-səs-ˈbe-ˌlī \

Definition of casus belli

plural casus belli play \ˈkä-ˌsüs-, ˈkā-ˌsüs-\

: an event or action that justifies or allegedly justifies a war or conflict

Recent Examples of casus belli from the Web

And that’s just in one Bush department, thus leaving out the false casus belli in Iraq or the yawning deficits or the financial collapse of 2008.

— t.a. frank, The Hive, "A Note to Woke Washington: The Bush Administration Was So Much Worse," 4 May 2018
In the days following the session in Burbank, Sitrick worked with Shamrock executives on a letter of resignation from Roy to Eisner that not only would deny the chairman the pleasure of ousting Roy but would be a casus belli as well.

— Los Angeles Magazine, "Harvey Weinstein’s New Crisis PR Man Once Handled Rush Limbaugh, R. Kelly, and Accused Catholic Priests," 19 Dec. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'casus belli.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.