Congress gets to decide on a declaration. The AP style guide is basically the industry standard, and their track record of describing things accurately is why it is the way that it is. So in summary, we’re talking about two different applications of the word “war” here.

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congress decides we are at war, except... we've kind of skipped that formality for a long time.

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congress hasn’t declared war since 1941 and we’ve been in plenty of wars since then

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