>Congress specifically gives the president the power to counter unfair trade practices by foreign governments. The president executes the laws, he doesn't dictate them.

The Congress has increasingly delegated rulemaking to the Executive through various forms of Authorization Act that empower the Executive to arbitrarily dictate Administrative Law.

I wouldn't exactly rank Congress highly in being the rulemaker here. There's been no great change, upset, or active reaffirmation of the process in years.