i have a friend in a u.s. technology company, and they simply cannot beat the chinese version of their product in both price and features despite being the creator of the product category decades ahead of others. the chinese companies copied the design but have now exceeded it, so the u.s. product does very poorly in china.
so what it sounds like to me is that the u.s. sees the writing on the wall, which is all due to their own actions and corporate greed over the past few decades, and so now is making a hail mary in a trade war. it doesn't seem like a good idea when it likely won't be long until china has the upper hand.
so it seems it basically comes down to trump taking his poor understanding of dynamics and abusing the u.s. government's and people's need for a "war".