Tensions between Houthi rebels and their ally, former Yemeni President Ali Abdullah Saleh, have escalated since their formation of a self-proclaimed joint government Nov. 28. The process wasn't easy to begin with, and challenges continue to threaten the tenuous arrangement.

The biggest problem facing the newly formed, large government is its lack of legitimacy because no country has recognized it. Saleh was ousted in November 2011 during the Arab Spring, and Abed Rabbo Mansour Hadi, his vice president, took over. However, Hadi was forced to resign in January 2015, and Houthi forces loyal to Saleh declared control the following month. Hadi, backed by Saudi Arabia, soon renounced his resignation and became head of the internationally recognized government, as fighting continued.

Now, under on-again, off-again negotiations through the United Nations, it is hoped Hadi eventually will transfer his power to a new government. But UN-sponsored negotiations in Kuwait failed in April, and the formation of a joint political council Aug. 6 was followed by nearly four months of faltering talks.

The Middle East Eye cited "informed sources" as saying one agreement Hadi rejected in October called for him to transfer his power to a newly named vice president after the Houthis leave Sanaa and surrender their large weapons to a third party. The vice president would then appoint a prime minister to form a government designed to represent all Yemenis.