casus belli

ca·​sus bel·​li | \ ˈkä-səs-ˈbe-ˌlē How to pronounce casus belli (audio) , ˈkā-səs-ˈbe-ˌlī How to pronounce casus belli (audio) \
plural casus belli

Definition of casus belli

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

Examples of casus belli in a Sentence

Recent Examples on the Web By exposing this plan, the Biden administration sought to undermine its emotional power and stop the Kremlin from manufacturing a casus belli, or justification for war. Scott Radnitz, The Conversation, 17 Feb. 2022 India was itching to intervene militarily but lacked a cast-iron casus belli. Tunku Varadarajan, WSJ, 18 Mar. 2022 The Tonkin Gulf incident, which provided a casus belli for the Vietnam War, gets a single sentence. Fred O’brien, National Review, 3 Mar. 2022 But invocations of genocide represent more than just a superficial casus belli. New York Times, 19 Feb. 2022 Russia had all but warned that this would be casus belli. Mario Loyola, National Review, 17 Feb. 2022 Also on Wednesday, a senior Biden administration official, who spoke on condition of anonymity, accused Moscow of trotting out a bevy of false claims with the intention of using them as a casus belli for an incursion into Ukraine. Los Angeles Times, 17 Feb. 2022 False flag attacks are risky, while leaders seeking to manufacture a casus belli can select from a range of subtler and less costly alternatives. Scott Radnitz, The Conversation, 17 Feb. 2022 Analysts say a purely political casus belli could also arise, such as a Russian claim that American, British and other NATO countries are providing weapons to Ukraine that pose a risk to Russian security. New York Times, 25 Jan. 2022 See More

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.

First Known Use of casus belli

circa 1841, in the meaning defined above

History and Etymology for casus belli

New Latin, occasion of war

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Time Traveler for casus belli

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The first known use of casus belli was circa 1841

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Dictionary Entries Near casus belli


casus belli

casus foederis

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Last Updated

8 Apr 2022

Cite this Entry

“Casus belli.” Dictionary, Merriam-Webster, Accessed 20 May. 2022.

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