President Trump followed through with his threat: Since June 2018, steel and aluminum imports from the EU are subject to tariffs. Trump justifies these with national security considerations. However, EU steel and aluminum do not threaten the national security of the United States. Breaches with WTO law should not be tolerated. The EU’s rebalancing measures are thus an important political signal. At the same time, tit-for-tat retaliation will harm everyone. Therefore, both sides must return to the negotiation table.