As Higgins86 said above, this isn't 1946 (or 1941, when the U.S. entered the WWII). The idea that Trump's move is to make the U.S. self-sufficient in case a world war broke out is silly. Think about it. Consumers need to pay 25% more for the metal in their next car because we need prepare for the next war?
These metals are only a piece of the strategic puzzle. Many of the chips used in missiles, aircraft and other weapons are made in foreign countries. Rare earths, used in electronics, are also largely in foreign countries. The world is interdependent today.
The stated reason for these tariffs was 'dumping by China and India,' not a need to have complete self-sufficiency in preparation for war.
Oh, I disagree with your first sentence ["congress (sic) finally stepping up top the plate to increase the military budget"]. Congress has funded the military lavishly to the point that the U.S. spends more than most of the remaining countries combined. The Pentagon isn't denied anything.