Pausing foreign applications to American universities is a terrible idea

The Trump administration’s decision to pause all visa interviews for foreign students who want to study in America, pending a review of how applicants’ social-media posts are vetted, is yet another escalation in the power struggle over who controls the world’s best universities. The policy may be modified. It may prove less onerous than it looks at first glance. Even if that happens, though, this is another blow to a great American success story.