An informative post by Curzon at Coming Anarchy
….The Saudis are guilty of aggravating and prolonging the conflict. Wary of taking too many losses on the ground and unable to do much by air and sea, they have recruited the Hashed, a local tribe, to fight against the Huthi, the tribe central to the Shia rebels. The Hashed have several incentives to continue fighting for as long as possible-they have a long-standing feud with the Huthi, and make a great deal of money from fighting for the Saudis, and may be coming up with schemes to prolong the conflict. According to a source of Al Jazeera:
If [the Hashed are] given the mission of taking a particular mountain, for example, they’ll call up the Huthi leaders and tell them: ‘We’re getting five million riyals to take the mountain. We’ll split it with you if you withdraw tonight and let us take over’… After the tribesmen take charge, they hand it over to the Saudis… The next day, the Huthi return and defeat the Saudis and retake the mountain… It’s been happening like this for weeks.