Despite its heady ambitions, the coalition’s bifurcated military efforts—a UAE-led ground force, and the Saudi-led air campaign—have never quite coalesced. Yemen’s internal political dynamics have also hobbled the coalition. Rancor developed rapidly between Yemeni President Abd Rabbu-Mansour Hadi and the UAE, with Hadi accusing Abu Dhabi of usurping governance in the south, and Emirati officials outraged over the apparent corruption and uncoordinated decisions of Hadi’s own rule. Meanwhile, Riyadh’s seeming lack of urgency to wrap up the war (the Saudi Crown Prince has repeatedly asserted that “We will stay until we win”) stood in sharp contrast to the UAE’s early recognition of the need to pivot to a political process, only made more urgent by the disproportionate casualties its forces have suffered.

Prior to the war, Yemen had been one of the few success stories of the Arab Spring. When its longtime despot, former President Ali Abdullah Saleh, faced severe political unrest in 2011, the collective pressures of the United States, Gulf Cooperation Council, United Nations, and key European states secured Saleh’s peaceful exit and set the country on the road to democratic transition. Saleh, never resigned to his removal from power, reemerged in 2014 as the transition reached a critical stage, partnering with the Houthis and enabling their remarkable success in scuttling Yemen’s political transformation and the Hadi government.

Six months ago, that highly transactional alliance blew apart spectacularly, with the Houthis executing Saleh and his party cohorts in cold blood as he looked to switch sides to the coalition. For perhaps the only time in this conflict, the Houthis found themselves—briefly—in the unfamiliar public glare of criticism, including inside Yemen. But the Houthis fight on, with Iran’s carefully cloaked support, as international censure has settled immutably on the Saudi-led coalition.

All the while, Iran’s influence in the broader region has grown. Russia’s support has ensured the survival of Bashar al-Assad in Syria and enabled Iranian and foreign Shia fighters to embed in the country. Meanwhile, the Iran-backed Hezbollah deployed to Syria and won resoundingly at the ballot box in Lebanon. Iran is also flooding Baghdad with money and currying influence to ensure its partners form the next government.

Washington poses a still more complicated picture for the coalition. The latter’s messy prosecution of the war, mounting indicators of famine and disease in a population on the brink even before the conflict, and the absence of a political process for 18 months have sparked a backlash in Congress. A bipartisan Senate effort to press the Trump administration to suspend military support to the coalition failed by a narrow margin, and is certain to be repeated.