At the risk of sounding like an anarchist, why in the world would there be such a thing as "an international trade law"?
The Founding Fathers would be enraged that the US would cede it's sovereignty to an international governing board, especially when it comes to how the US - a sovereign nation - negotiates, enforces or withdraws from it's own trade agreements.
Joining the WTO was a HUGE mistake. It was designed expressly to take pressure and responsibility from precisely where it should be and solely - our duly elected political representatives.
Joining the WTO and the IMF was no mistake when our country was economically dominant and could use these agencies to strong arm weaker economies into complying with U.S commercial interests.
Unfortunately, there are now several economies(EU, China, Japan...etc) of comparable scale, and they want to use these agencies to further their own interests.