U.S. and Yemeni officials say the U.S. counterterrorism strategy in Yemen has all but collapsed as the country descends into chaos.

Operations against militants have been scaled back dramatically amid the fall of the government and evacuation of U.S. personnel. What had been consistent pressure on Yemen's al-Qaida affiliate has been relieved, the officials say, and a safe haven exists for the development of an Islamic State offshoot.

It's a swift transformation for an anti-terror campaign President Barack Obama heralded just six months ago as the template for efforts to fight the Islamic State in Iraq and Syria. The shift has left Obama open to criticism that he failed to anticipate the risks of a strategy that aims to put fragile governments and beleaguered local security forces at the forefront.