Understand. But, how do you suggest that we combat a country like China that is trying to destroy our economy by flooding the market with government subsidized products that are often the result of them stealing our companies intellectual knowledge and patents? These are not capitalistic countries. They are communist countries using the marketplace as a weapon.
Another huge problem with all of this is that we are our own worst enemy - our own corporations started the job migration to other countries when it became more profitable for the companies & shareholders to ditch spending on our own future and American workers. This really got going after WW2, when American factory machining was wearing out and needed to be replaced, they discovered they could make the items in other countries for a pittance, and profit would be very great, and well, you see where many of our industries ended up going, as they built new factories in the other countries and we trained their workers, rather than investing here.
It was very shortsighted for the American economy and worker, but very profitable for the shareholders. The same thing has happened to the Japanese, as they were once a prime target of these moves, then other countries became better at it and did it cheaper, and their jobs and factories started migrating for greater profit. It goes on and on, country by country. I could have went to CHINA for MDAC in the late 80's early 90's when we were teaching the Chinese how to build jet airliners, to teach them how to supply and run their factories (this is a true statement).
Now, automation will further denigrate the ability of the American worker to thrive and prosper, as robots only need programming, power and maintenance (and a couple of folks can service a whole fleet of robots), no insurance, no healthcare, no pension, no salary. If we also stop immigration, we will also harm our economy as it was basically built on the premise of an ever expanding population requiring more goods and services, and will also harm our programs like Social Security and Medicare as there are less and less viable contributions to the pool.
We are in a tough spot that we basically created, and isolationism isn't the answer, it will take us even further down the tunnel of no return. We could go the even further into the "make war & profit" arena, but that would no doubt result in the deaths of million/billions and maybe destroy us all, as we can't take on everybody and hope to survive (we'd would have had to do that after WW2, as it was maybe possible at that time).
Every country wants to use the world marketplace to their best ability, and we gave away our competitive edge. The jobs might come back (well, some might) if we work for a pittance like the workers in the countries that inherited our jobs and factory base. When I talk to young folks about the future, I stress the education part as we will need highly specialized workers to hope to stay near the top. It will be a tough road ahead.