The Trump Administration has in effect shut down the World Trade Organizations power to dictate who can apply tariffs on who. It all comes down to the “appellate body” that hands down the final ruling when member nations bring a trade dispute before the WTO.
Normally, when member states have a trade issue they take it the WTO to resolve. The WTO empanels a group of trade judges to rule on the dispute. If the involved parties are dissatisfied with the finding they can take their case to the appellate body for a final hearing. Parties are then allowed to apply countervailing tariffs to offset the damage done by the nation found to be violating the standards of free trade.
The appellate body normally has seven members who are normally appointed by the dispute settlement body for a four year term. Tomorrow, two members are ending their term and The United States is holding up the appointment of any more members, leaving only one person sitting on the appellate body, thus rendering it powerless to rule. More
Canada, the EU and Norway have declared a work-around alternative that they welcome other nations to participate in with them. Here