What's wrong with restrictions on trade? Alexander Hamilton's 1791 Report on Manufactures spells out why they are so damn important, and this line of thinking ruled American policy for the next 150 years. America industrialized itself using protectionism. It's trade liberalization that is the recent anomaly, although it has now run for enough decades that its promise of "better for everyone, honest!" can be evaluated against reality. The results are in: the benefits accrued to capital, who saw a many-fold return on their assets, and the costs accrued to labor, who saw stagnant wages for decades.

If you want the macroeconomics assessed in detail and the usual apologetics evaluated against evidence, I refer you to "Trade Wars are Class Wars" by Klein and Pettis.