That's nice. Let us know when you actually understand the thing, will ya?
The excerpt that you post does not give congress the authority to prevent Americans from trading with people of other nations.
Wrong-o.
Regulation is not banning.
Wrong. Regulation can include banning any and all trade with specific countries, or it can ban trade in specific goods and services.
Unless, of course, you're saying that Bernie Schwartz had an unlimited right to sell missile technology to the ChiComs, who now point those Loral-improved missiles at us.
Perhaps you should educate yourself on the word regulate. In this sense it means to "facilitate" and cannot be construed to mean "prevent" or "ban" by any stretch of the imagination.