This article proposes that foreign-imposed regime changes (FIRCs) make civil war onset more likely when they damage state infrastructural power, as in the context of interstate war, and when they change the target’s political institutions as well as leadership. Using rare events logit to analyse civil war onset from 1920 to 2004, it is found that interstate war and institutional change are virtually necessary (though not sufficient) conditions for an FIRC to cause a civil war. Many control variables are included. The results are robust to different research design specifications; nevertheless, they cannot confirm that occupation troops make an FIRC more likely to spark civil war.