Days of heavy fighting, which left at least 140 people dead in the Yemeni capital of Sanaa, came to an end on Sunday with the resignation of the prime minister and a tentative new peace deal. But the deal, which was signed by representatives of the Houthi movement and Yemeni President Abd Rabu Mansur Hadi, is unlikely to be the sort of long-term agreement the country has been searching for since former President Ali Abdullah Salih stepped down in early 2012.

In carrying out its four-day blitz through Sanaa, which included taking over state television headquarters and several government buildings, the Houthis — a sophisticated rebel movement — were both flexing their political muscle and continuing a bitter blood feud that stretches back a decade.

Over the past two years the Houthis have moved far beyond their narrow sectarian origins. They have broadened their appeal beyond their traditional power base of Zaydi Muslims — a branch of Shiite Islam that is relatively close to Sunni Islam — and in the process become Yemen’s primary opposition group. They are also, as the latest agreement makes clear, the closest thing Yemen has to a kingmaker. The Houthis may not have enough power to impose their will upon the rest of the country, but they now have enough supporters and weapons to act as an effective veto on Yemen’s central government. […]