European leaders said that they would respond firmly to higher levies on steel and aluminum, but they had yet to say what that retaliation would look like. Protectionism (Trade), International Trade and World Market, Customs (Tariff), Steel and Iron, Aluminum, European Commission, European Union, Trump, Donald J, von der Leyen, Ursula European leaders said that they would respond firmly to higher levies on steel and aluminum, but they had yet to say what that retaliation would look like. NYT > Business