The White House, engaged in a trade dispute with China, has announced exemptions to steel and aluminum tariffs for several allies, including the European Union, and is marginalizing the World Trade Organization. Below is a selection of notable reactions to the protectionist moves.

“If attacked, we will respond without weakness. Everyone needs to understand this, and I think I can say that the American strategy is a bad strategy. ... We talk about everything, in principle, with a friendly country that respects the rules of the W.T.O. We talk about nothing, in principle, when it is with a gun to our head.”

Emmanuel Macron, France’s president.

“Maybe it’s a way to exert strong pressure on the European Union, to start some sort of a negotiation with a revolver to our head. That’s a strange way of negotiating with an ally.”

Charles Michel, Belgium’s prime minister, explaining why he still had “doubts” after the European Union was among several American allies granted an exemption to steel and aluminum tariffs.