The US has for too long allowed other countries to take advantage of us trade wise. Previous presidents and congress have not looked out for our best interests.
Whether the trade wars will be good or bad long term remains to be seen. If we commit, we need to commit fully and be prepared for the short term hurt because it will be there. China seems willing to wait us out as it really doesn't have to answer to its people. The US on the other hand will have plenty of folks screaming about the pain and many leaders will be ready to cave in quickly.
I fully agree that we should not rely on Chinese electronics for our defense systems, that really should be domestic.
Trade war could well be an opportunity for other 3rd world countries that could ramp up manufacturing. That would put the squeeze on China but certainly won't be quick. I read where Vietnam has no excess manufacturing capacity because so much production has been moved there. Africa may well be where more manufacturing is shifted but outsiders won't invest unless a given country has a stable government and they are hard to find on that continent.
Our short term hope for jobs shifting back here is likely for smaller firms that can ramp up quickly, don't know if that is doable.
I personally hope we hold all unfair trade partners feet to the fire to get a fair shake, but I am in a position where my pain won't be bad. If it would cripple my finances, I would likely see things differently