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
To legitimize its war, China would try to point to provocations by Taipei and Washington—which is why the no-deadline pledge would incentivize them to refrain from acts that Beijing could hold up as compelling casus belli.
—
Stephen Wertheim, Foreign Affairs, 28 Oct. 2025
Analysts have viewed Bolsonaro’s trial as the casus belli that prompted Trump’s aggressive moves against the country.
—Brady Knox, The Washington Examiner, 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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Stephen Wertheim, Foreign Affairs, 28 Oct. 2025
Analysts have viewed Bolsonaro’s trial as the casus belli that prompted Trump’s aggressive moves against the country.
—Brady Knox, The Washington Examiner, 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 8 Nov. 2025.
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