By Samia NakhoulBEIRUT, July 14 (Reuters) - Having choked off shipping through the Strait of Hormuz, Iran is now signaling it could play its most dangerous card yet: using Yemen's Houthi allies to shut the Bab el-Mandeb gateway to the Red Sea, opening a new front against Washington and putting two of the world's most vital energy arteries at risk.

Houthis closed the Bab el-Mandeb Strait, threatening 60% of Middle East oil exports. Closure by September 30 at 17.5% YES.

Iran shifts focus to the Red Sea, leveraging Houthi rebels amid US tensions. Strait of Hormuz traffic returns to normal by August 31 at 12.5% YES.