Do World Trade Organization laws still exist?

It is time to ask: For the U.S., does the international law of the World Trade Organization still exist?  

As part of an escalating tit-for-tat of trade restrictions between the U.S. and China, the Chinese government has banned the export of several critical materials that have both commercial and military applications in high-tech production. This Chinese action may or may not be eligible for a national security exception to the general rule in WTO law that forbids export bans and other export restrictions.