BAB AL-MANDAB STRAIT — Yemen's Houthi military spokesman announced conditions that would trigger the group's full entry into the war against Iran, including warnings they could target the Bab al-Mandab Strait. The Houthis signaled they could move against the strait through which roughly 10 percent of the world's seaborne oil passes.

The Houthi military spokesman laid out specific conditions that would trigger the group's full entry into the war. One of the conditions is that any country actively participating in the US-Israeli war against Iran would trigger the group's full entry into the war.

On March 28, Yemen's Houthi rebels fired their first missiles at Israel since the Iran war began. The Houthis are designated as a terrorist organization by the United States.

One scenario for full Houthi entry into the conflict is a resumption of their Red Sea blockade similar to operations during the Gaza war. Another scenario for full Houthi entry into the conflict is strikes on Saudi energy facilities on the Red Sea, including the port of Yanbu. The port of Yanbu is an overland alternative that carries Saudi crude from the Persian Gulf coast to the Red Sea, bypassing the Strait of Hormuz entirely. A scenario for full Houthi entry into the conflict is potential strikes against the US aircraft carrier group in the Arabian Sea.

Iran has effectively closed the Strait of Hormuz. Energy markets research firm HFI Research estimated that a Houthi move on the Bab al-Mandab Strait would put an additional 4 million barrels per day of Saudi crude exports at risk. "It won't be as bad as the disruption in the Strait of Hormuz thanks to the Suez Canal, but the market won't care," HFI Research said.

"This, in my opinion, is an indirect message to the Gulf and particularly Saudi Arabia, warning them against joining the war against Iran, or letting US forces use more of their bases," said Michael Horowitz, an independent defense analyst based in Israel.

Danny Citrinowicz, a security analyst at the Institute for National Security Studies in Tel Aviv, said "While Houthi strikes against Israel should not be dismissed, from Iran's perspective, as part of a broader economic campaign against the United States, the central issue lies in their demonstrated ability to threaten critical energy transit routes at both maritime chokepoints." Citrinowicz said "With each passing day of the conflict, particularly in light of its expanding scope against Iran, the likelihood of this scenario materializing continues to grow. It is increasingly not a question of if, but when."

On March 27 in Sanaa, Yemen, Houthi supporters demonstrated in solidarity with Iran.