We have "Managed Trade" and since the 1940s it has been purposely managed to the US detriment.
At Berrton Woods the US and Britain had a conference to set up a post WW2 international finical and trade system. The Conference, run by British and US socialists, communist sympathizes and "New Dealers", crafted a new financial/trade system for the post war world. One of their theories was the war was caused by wild swings in trade and international finance.They crafted a system that was designed to smooth out those swings and promote global stability.
The theory was, that the US Economy was so big, diverse and strong, it could adsorb other countries finical/unemployment woes thus help prompt peace and stability.This expanded during the Cold War as the US used it economic muscle to counter the expansion of communist influence around the world.
What Trump is doing is challenging the assumptions and theories of the "Managed Trade" Globalists. Rather then cling to a 70 years old theory, maybe we need to realize that both World War 2 and Cold War are long over and we need a new trade system.
Excellent comment!