In Yemen, Shiite Houthi rebels have overtaken the presidential palace and are standing guard outside the residence of President Abdu Rabbu Mansour Hadi in what top Yemeni officials are calling a coup. But the rebels appear to have stopped short of forcing Hadi’s resignation, instead demanding he comply with the terms of a power-sharing deal reached in September when the Houthis seized most of the capital Sana’a.