Iran and Saudi Arabia are edging dangerously closer to direct conflict, analysts warn, after Riyadh resumed major air strikes on Yemen’s Tehran-allied Houthi rebels this week, ending a four-year lull. More than 100 Saudi warplanes bombed rebel positions on Monday, enabling Yemeni government forces to retake much of the Red Sea coastal territory the Houthis seized last month. The Houthis had been aided by embedded Iranian military advisers. Analysts expect the Houthis to retaliate by intensifying...