What would Britain do if Germany captured Paris and knocked France out of World War I?
Short answerBritain could revert to blockade and subsidized coalition warfare, making any peace temporary.
NotesCapturing Paris alone might not have ended French resistance because plans existed to move the government and continue the war. World War I France was not politically or militarily identical to France in 1940, so the fall of the capital need not be decisive. If France nevertheless left the conflict, Britain could withdraw its army, blockade Europe, and finance other land powers in a strategy resembling the Napoleonic Wars. Any negotiated peace would be fragile, with both sides rearming for another confrontation.