Britain, France, and Germany are rightly preparing sanctions over Russia’s Aug. 20 poisoning of investigative journalist and opposition politician Alexei Navalny. The Trump administration, however, is remaining silent.

Silent, at least, in terms of taking action over Vladimir Putin’s breach of the Chemical Weapons Convention. While both President Trump and Secretary of State Mike Pompeo have raised concerns over Navlany’s poisoning, neither has given reason to think that the United States will join the European sanctions effort. It’s a serious mistake.