[jyl]

I guess we should put tariffs on every country not at a wage and environmental parity with ours? India, Mexico, Brazil, Vietnam, Indonesia, Egypt, Russia, basically everyone not in the G10? Presumably they would do the same with us. So you now have big tariffs on, oh, 1/3 of world trade.

US manufacturers then pay much higher prices for the materials and components they import from China and all the other "low-cost" countries. Far higher than paid by, say, German companies or Japanese companies or UK companies. So now US goods are uncompetitive versus those G10 countries. Our balance of trade with China improves, but our balance of trade with the rest of the G10 falls apart.

Maybe we put tariffs on the G10 countries too? So now there are big tariffs on 2/3 of world trade?

The Great Depression and the events leading up to it should show you why that is a very bad thing.