WASHINGTON (AP) — The U.S. counterterrorism strategy in Yemen has all but collapsed as the country once hailed by President Barack Obama as a model for fighting extremism descends into chaos, according to U.S. and Yemeni officials.

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

It's a swift and striking transformation for an anti-terror campaign 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 light footprint strategy that aims to put fragile governments and beleaguered local security forces, not the U.S. military, at the forefront.

In response, administration officials argue that the U.S. has no choice but to rely on proxies in the terror fight if it wants to avoid American ground troops becoming bogged down as they did in Iraq and Afghanistan.

Yet Barbara Bodine, a former U.S. ambassador to Yemen, said even the most optimistic regional experts did not share Obama's view in the fall that the Yemen campaign was a model of success.

"It was being defined in terms of what we were doing to develop local forces and use drones and counter the immediate and real security threat," said Bodine, now director of the Institute for the Study of Diplomacy at Georgetown University. "But what we hadn't done, certainly had not done visibly enough, was get at the economic and governance issues that were driving the problem."

Since September, Houthi rebels linked to Iran have ousted President Abed-Rabbo Mansour Hadi and dissolved the parliament. Al-Qaida in the Arabian Peninsula (AQAP), which has been affiliated with some of the most serious attempted attacks on the U.S. since Sept. 11, 2001, has sought to exploit the chaos. Last month, the U.S. shuttered its embassy in the capital of Sanaa, and over the weekend the remainder of American military personnel withdrew from the south of the country.

"Certainly, repositioning our forces out of Yemen will make our fight against AQAP more difficult. There is no question about that," Pentagon spokesman Col. Steve Warren said Tuesday.

Since Obama took office, the U.S. has poured millions of dollars into efforts to stabilize Yemen's government and boost its security forces. Under Hadi, U.S.-trained Yemeni troops were mounting regular raids to kill and capture al Qaida militants, punctuated by occasional CIA drone strikes aimed at senior figures.

The strategy has been guided by the central tenets of Obama's philosophy for fighting extremists overseas: targeting extremists from the air, bolstering the capacity of foreign governments and avoiding putting large numbers of U.S. military personnel on the ground in dangerous countries.

Now, virtually all of the Yemeni troops that had worked with the U.S. are engaged on one side or another of a three-pronged political struggle between the remnants of the Hadi government, supporters of former President Ali Abdullah Saleh, and the Houthi faction, U.S. officials say. The officials insisted on anonymity because they were not authorized to speak by name about sensitive intelligence assessments.

CIA drone strikes will continue, the officials said, but there will be fewer of them. The agency's ability to collect intelligence on the ground in Yemen, while not completely gone, is much diminished. There have been just four U.S. drone strikes reported in Yemen this year, according to Long War Journal, a web site that tracks the attacks. That is about half the pace that last year resulted in 23 strikes over 12 months.

___

Follow Julie Pace at http://twitter.com/jpaceDC and Ken Dilanian at http://twitter.com/KenDilanianAP