Secretary of State John Kerry flew to Saudi Arabia on Wednesday to take on the challenge of explaining a potential deal over Iran ’s nuclear program to the American-allied conservative monarchies of the gulf. In the Saudi capital, Riyadh, Mr. Kerry plans to meet with King Salman and to consult with foreign ministers from Bahrain, Kuwait, Oman, Qatar and the United Arab Emirates, who are also flying there. Like Israel, which opposes the potential deal, Saudi Arabia and other Arab nations in the region see Iran as an opponent. They are concerned about the terms of the deal, which would be limited in duration and would allow Iran to retain some of its nuclear infrastructure. Mr. Kerry met here in Switzerland for three days of talks that also included the United States energy secretary, Ernest J. Moniz, and Ali Akbar Salehi, the director of Iran’s Atomic […]