President Donald Trump’s economic D-Day is already hurting the Iranian regime’s revenues, but unilateral U.S. sanctions can only do so much. If the president wants Iran to fold, he’ll have to play a much better card — cutting it off from China by enforcing tough U.N. embargoes.

Despite its name, Trump’s Operation Economic Outcast does not block Beijing’s vital support for the regime in Tehran. In fact, at a recent summit, China and Iran jointly condemned and vowed to defy the new U.S. strategy.