Honestly, other nations will end up selling and getting better to other nations, whereas USA will end up staying behind, because if others can't sell to USA, you think they will just keep getting American products?
If Hyundai can't sell to USA, you think Ford could sell to them? Of course not, and that would cause so much problems. And this is terrible for small business but even worse for big ones. Think of it, 100 million dollars spent by some big company to get something, could become 150 million with new tariffs, how are they not going to make the product sold for more? They will. Apple for example is the biggest one and that should be giving you enough example that none of these will mean anything in the end.
Your right this is what America under trump is failing to realize that if America doesn't wants other countries to sell their products to America they too should be prepared not to sell their products to other countries what I see is that America is trying to dictate what others countries should sell or not especially as it concerns the production capacity of other nations adding a trade tariffs other nations is a threat to These countries and you expect them to react.
The world is going towards a period where every countries will be dealing on the basis of mutual respect for each other this can be done on the basis of mutual trade importing and exporting from each other between two countries not a situation like this where only one country dictates what happens in the world global trading market