After four years of stalemate, Yemen is teetering on the verge of all-out war again, further threatening Middle East stability. Fighting is escalating between the Iran-backed Houthi militia and Yemeni government forces, as well as across borders with Saudi Arabia. Analysts say all sides have incentives to ramp up conflict. The Houthis, who seized Sanaa in 2014, want more power and resources. Since a 2022 truce, they lack oil revenue and face worsening economic conditions in their territory, increasing civilian resentment. They demand lifting restrictions on ships and planes, Saudi war reparations, and full Saudi withdrawal. "The Houthis have no incentive to de-escalate," said Ibrahim Jalal, a Yemeni researcher and policy adviser.

For Iran, the Houthis are a useful ally controlling Red Sea trade routes. Since the U.S.-Iran war began in February, Saudi oil shipments have rerouted through the Red Sea. In July, Houthis declared a blockade on Saudi shipping, disrupting global trade and pressuring the Trump administration, said Baraa Shiban of the Royal United Services Institute in London.

The internationally recognized Yemeni government sees a chance to reclaim territory. Previously restrained by Saudi Arabia, government forces have received stepped-up Saudi support and unification efforts. They aim to "weaken the Houthis significantly," said Jalal.