A brighter light on Russian war crimes

On Monday at the Holocaust Memorial Museum in Washington, Secretary of State Antony Blinken seemed to send a subtle and timely message to officials in the Kremlin. He designated the military slaughter of Myanmar’s Rohingya Muslim minority in 2016-2017 as genocide. The possible message: Any official in Russia who assists in the intentional mass killing of civilians in Ukraine could someday face a similar prospect of international justice.

“By learning to spot the signs of the worst atrocities, we’re empowered to prevent them,” Mr. Blinken said.

With the announcement, the...