The US President may be looking for a deal with Iran, but first, he must rein in his ally Israel, which continues to pound Iran and Lebanon.

Donald Trump, whose administration has already eased some sanctions on Iran’s oil, could be looking for a deal, and Tehran could reciprocate if common ground is found. But for any diplomatic effort to progress, Mr. Trump must first rein in his ally Israel, which continues to pound Iran and Lebanon like an unhinged bully.