A couple of times I’ve gotten into debates on whether or not it takes two declarations of war (one from each side) to make a war. I say it doesn’t. Germany declared war on the U.S. on December 11th, and I don’t think the U.S. ever returned the favor. But I’m not sure … U.S. declaration of war on Germany is never mentioned anywhere, but maybe it’s thought to be too much a technicality to bear mentioning.
The U.S. and Japan both declared war on each other, so clearly two declarations can happen. I was just wondering if, in the traditional way of warmaking, each side was supposed to declare, or if one would suffice.