I have absolutely no right to get involved in any way with trade/commerce between Americans in the 50 US states.
When a third party nation is involved I am damn site well within my rights to get involved, actually it is my duty as a citizen to make sure this "trade" is fair and is in the best interest of my fellow citizens. Yes, I used the word fair.
It is none of your business whatsoever if I make a trade that is, in your opinion, unfair. All that matters is that the trade is legal (i.e., no drugs) and that I value what I've purchased more than what I've sold.
You sound like Bloomberg. Who the heck are you to worry over what other Americans buy and sell? We are citizens of the United States and that does not make us slaves to each other.
This is the old "common good" argument -- the one the liberals, socialists, and Fascists have relied on for a century. The "common good" is best served when each individual is left free to do what is in his own best interest.
Yours is a very authoritarian outlook.