I'm a consumerist at heart. As long as consumers get to consume, it does not matter to me whose industry is doing the producing.
I get that your foreign suppliers can turn on you and raise prices. I think the money you make during peacetime by not putting tariffs will let you buy more weapons and bribe more allies so that the foreign suppliers don't try anything too awful with the supply chains. Stockpiles can buy a lot of time to restart industry in an emergency or at least find a different foreign supplier.
Take a look at Russia, they are sanctioned by half the planet and they still keep going on a reduced industry because they had huge stockpiles of tanks, artillery and so on. Imagine something like that but with a military that doesn't suck. Nobody would even dare try a sanction.