The administration hard-sells reactor exports while shrugging off proliferation concerns.In Washington, learning comes hard. Officials may know when to back off when they’ve crossed wires with Congress, but in most cases, and in less time than you’d think, they’re back at it again. Take the State Department’s rush three years ago to seal a civilian nuclear deal with Vietnam. Secretary of State Hillary Clinton announced that the U.S. had initialed a draft agreement in July of 2010. It featured nuclear-nonproliferation provisions far looser than what Congress wanted. When the Hill found out, it threw a fit, the White House withdrew...