Metaphors are a thing. People can (mostly) tell the difference between a literal war and a metaphorical war.
I say '(mostly)' because while the 'war on Christmas' and WWII are clear cut cases, the war on drugs is an example that sometimes skirts closer to the border. Though it's still very much a metaphorical war.
I'm not sure this is accurate.
We have plenty of "wars" that aren't wars. Such as the annual "war on Christmas".
Do we recognize them as "wars"? Or do we just use the word?