With President Ali Abdullah Saleh clinging stubbornly to power, Yemen is descending into chaos. For a third day, state forces fought in the streets of the capital with a powerful tribal confederation. There have been at least 44 deaths as violence spreads and more sheikhs turns against the president, who had committed to stepping down, but then reversed his position and announced he would stay. But the defection of the Hashid tribe is a blow to the president, who would have received immunity from prosecution under the deal. Western leaders including President Obama are watching anxiously, worried that the turmoil could help al Qaeda in the Arabian Peninsula, a dangerous branch of the terrorist group.