President Trump now faces the gravest test yet to his leadership.

Russia’s latest aggression in the Sea of Azov is for Trump the analogy of what Russia’s 2014 downing of a Malaysian Airlines jet over Ukraine was for former President Barack Obama. Obama failed that test catastrophically, refusing pleas by our Western allies to truly confront Putin over these murders. This showed Putin that he had open season to challenge American interests. In the final two years of his presidency, Russia’s escalation in both Ukraine and Syria gave bloody testament to Obama’s error.