Director of National Intelligence Dan Coats told Congress last week that America’s spooks believe Iran is still complying with Barack Obama’s nuclear deal. This may be technically true, but now comes the head of Tehran’s nuclear agency to say Iran has been preparing to break out from the start.

“We knew that [the Westerners] would ultimately renege on their promises,” said Ali Akbar Salehi in an Iranian television interview last month. “Not only did we avoid destroying the bridges that we had built, but we also built new bridges...