Leaders of Islamic nations condemned last month’s attacks on Saudi Arabian oil facilities and ships off the coast of the U.A.E that have been blamed on Iran and its Yemeni Houthi allies, saying the international community should preserve the region’s stability. The Organization of Islamic Cooperation held a summit in Mecca a day after back-to-back emergency meetings of Gulf and Arab leaders, who accused Tehran of threatening global oil supplies and maritime traffic. Saudi Arabia called the emergency summits following attacks on oil installations in the kingdom, and on tankers heading toward...