Other forms: revanches
In politics, revanche is when one country retaliates against another by reclaiming territory that's been lost. A focus on revanche can often lead to military conflict.
The French word revanche means "revenge." The word was first used in a political context in the 1870s after the Franco-Prussian War. French nationalists were determined to get back at the German confederation by reclaiming territory they'd lost, and their single-minded focus on this retaliation came to be known as revanche. The term is still around, used to describe modern political events like the 2022 invasion of Ukraine, which Vladimir Putin claimed was lost Russian territory.