U.S. President Trump decided to impose tariffs on steel and aluminum imports. An investigation by the U.S. Department of Commerce had come to the conclusion that these imports threatened the national security. The tariffs came into effect in late March 2018. The EU was exempted until the end of May 2018. The EU is also currently conducting a safeguard investigation for steel and requested consultations with the United States at the WTO. These are steps in the right direction.
Short version of the position paper “U.S. Tariffs on Steel and Aluminum“