A maritime incident could carry the altered American political situation into war. British practice in the First World War and the Napoleonic Wars provides a model: seize contraband cargo, send the neutral ship back, and let a court decide the dispute. Most neutrals might accept that process reluctantly, but repeated interference could provoke a sharper crisis. Removing Japanese personnel from an American ship offers another trigger, compared here with the 1940 Asama Maru incident. Blockade practices could therefore produce a usable casus belli once the political alignment already existed, although escalation would not be inevitable.
Chapter · 59:49-1:01:13
Blockade and an American casus belli
British interception of American trade with Japan could turn an already contrived political alignment into open war.