Foreign ministers from Egypt, Turkey, Saudi Arabia and Pakistan gathered before dawn Thursday in Riyadh for talks aimed at finding a diplomatic off-ramp to the war in Iran. But there was one big problem, according to Arab officials involved in the discussions: finding a counterpart in Iran to negotiate with. Earlier that week, Israel killed Iran’s national security chief, Ali Larijani, who had been considered a viable partner who could engage with the West. Egyptian intelligence officials managed to open a channel with Iran’s Islamic Revolutionary Guard Corps—the paramilitary group that protects the Iranian regime and is the country’s most…