casus belli
noun
ca·sus bel·li
ˈkä-səs-ˈbe-ˌlē 
ˈkā-səs-ˈbe-ˌlī
ˈkā-səs-ˈbe-ˌlī
plural 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
Analysts have viewed Bolsonaro’s trial as the casus belli that prompted Trump’s aggressive moves against the country.
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Brady Knox, The Washington Examiner, 4 Aug. 2025
Under Israel’s Begin Doctrine, which prescribes preventive warfare against adversaries capable of developing weapons of mass destruction, further ambiguity over the state of Iran’s nuclear program may serve as casus belli for future hostilities.
—Hasan T. Alhasan, Foreign Affairs, 4 Aug. 2025
That is the nature of this latest Israeli casus belli too.
—Melik Kaylan, Forbes.com, 16 June 2025
But what Putin can live with today may become a casus belli tomorrow.
—George Beebe, TIME, 1 July 2024
See All Example Sentences for casus belli
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Brady Knox, The Washington Examiner, 4 Aug. 2025
Under Israel’s Begin Doctrine, which prescribes preventive warfare against adversaries capable of developing weapons of mass destruction, further ambiguity over the state of Iran’s nuclear program may serve as casus belli for future hostilities.
—Hasan T. Alhasan, Foreign Affairs, 4 Aug. 2025
That is the nature of this latest Israeli casus belli too.
—Melik Kaylan, Forbes.com, 16 June 2025
But what Putin can live with today may become a casus belli tomorrow.
—George Beebe, TIME, 1 July 2024
See All Example Sentences for casus belli
Cite this Entry
“Casus belli.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/casus%20belli. Accessed 22 Aug. 2025.
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