Iran and six world powers agreed on parameters of a deal meant to block Tehran from developing nuclear weapons in exchange for the lifting of tough Western sanctions. U.S. President Barack Obama called it a “historic understanding” between two estranged nations after the outlines of a deal were announced Thursday in Lausanne, Switzerland. But he hinted at its fragility, saying the success of a final accord is far from guaranteed. “I am convinced that if this framework leads to a final, comprehensive deal, it will make our country, our allies, and our world safer. This has been a long time coming,” Mr. Obama said. “It is a good deal, a deal that meets our core objectives.” He said the deal, if completed, would block any pathway for Iran to acquire a nuclear bomb and argued the only real alternative to continued diplomacy is war. Negotiators would start drafting an […]