WASHINGTON >> Even as the Obama administration scrambles to confront the Islamic State and resurgent Taliban, an old enemy seems to be reappearing in Afghanistan: al-Qaida training camps are sprouting up there, forcing the Pentagon and U.S. intelligence agencies to assess whether they could again become a breeding ground for attacks on the United States.

Most of the handful of camps are not as big as those that Osama bin Laden built before the Sept. 11, 2001, attacks. But had they re-emerged several years ago, they would have rocketed to the top of potential threats presented to President Barack Obama in his daily intelligence briefing. Now, they are just one of many — and perhaps, U.S. officials say, not even the most urgent on the Pentagon’s list in Afghanistan.

The scope of al-Qaida’s deadly resilience in Afghanistan appears to have caught U.S. and Afghan officials by surprise. Until this fall, U.S. officials had largely focused on targeting the last remaining senior Qaida leaders hiding along Afghanistan’s rugged, mountainous border with Pakistan.

At least in public, the administration has said little about the new challenge or its strategy for confronting the threat from al-Qaida, even as it rushes to help the Afghan government confront what has been viewed as the more imminent threat, the surge in violent attacks from the Taliban, the Haqqani network and a new offshoot of the Islamic State. Former administration officials have been more outspoken — especially those who were on the front lines of the original battle to destroy al-Qaida’s central leadership.

“I do worry about the rebirth of AQ in Afghanistan because of what their target list will be — us,” said Michael Morell, the deputy director of the CIA until two years ago, whose book, “The Great War of Our Time,” recounts the efforts of the Bush and Obama administrations to destroy the Qaida leadership.

“It is why we need to worry about the resurgence of the Taliban,” Morell said, “because, just like before, the Taliban will give al-Qaida a safe haven.”

A senior administration official offered a different view, saying that the increased Qaida activity was more the result of Pakistani military operations pushing fighters across the border into Afghanistan than al-Qaida enlisting new Afghan recruits inside the country.

In October, U.S. and Afghan commandos, backed by scores of U.S. airstrikes, attacked a Qaida training camp in the southern part of the country that military officials said was one of the largest ever discovered. The assault, which took place over several days, pounded two training areas — one sprawled over 30 square miles — that featured elaborate tunnels and fortifications. As many as 200 fighters were killed, U.S. officials said.

Senior administration officials concede that there are other Qaida camps or bases, including at least one in Helmand province, though they are not certain exactly how many because they were made harder to detect after the October assault. The senior officials — four from three different federal agencies — spoke on the condition of anonymity to discuss confidential intelligence assessments.

A spokesman for the United States military in Afghanistan, Col. Michael T. Lawhorn, declined in an email to discuss “any current intelligence we may have on al-Qaida training camps.”

The two camps attacked in the fall were in a sparsely populated area of Kandahar province along Afghanistan’s southern border with Pakistan. Some of the facilities apparently were in place for up to a year and a half, undetected by U.S. or Afghan spies or surveillance aircraft.

“A lot of that is because, you know, it’s a very remote part of Kandahar,” Gen. John F. Campbell, the top U.S. commander in Afghanistan, recalled in a meeting with visiting reporters two weeks ago.

For months, Campbell has been sounding a warning about al-Qaida in the broader context of Afghanistan’s complex threat environment, telling Congress in October that Afghan security forces “have thus far proven unable to eradicate al-Qaida entirely.”

“Al-Qaida has attempted to rebuild its support networks and planning capabilities with the intention of reconstituting its strike capabilities against the U.S. homeland and Western interests,” Campbell said in his testimony.

The general said pressure on al-Qaida fighters from the United States and its Afghan allies had forced them to be “more focused on survival than on planning and facilitating future attacks,” but that continued pressure was necessary to keep al-Qaida from gaining new footholds.

The discovery of the large camp attacked in October raised questions about the U.S. military’s ability to detect and destroy a major Qaida stronghold in the country, more than 14 years after the U.S.-led invasion of Afghanistan drove out al-Qaida and toppled the Taliban government that supported them.

Campbell said at the time of the October raid that the camp was used by a new Qaida offshoot called al-Qaida in the Indian Subcontinent, or AQIS. Ayman al-Zawahri, al-Qaida’s overall leader, announced the creation of the affiliate in September 2014 largely in response to the rise of its rival, the Islamic State, which is also known as ISIS or ISIL. The wing, which U.S. analysts say has several hundred fighters, is believed to be based in Pakistan and focused on India, Pakistan and other nations in southern Asia.

AQIS fighters began migrating from sanctuaries in North Waziristan and eastern Afghanistan to the country’s southern provinces of Helmand and Kandahar last year, after Pakistan launched a military offensive in the region, said Seth Jones, an Afghanistan specialist at the RAND Corporation. Kandahar and Helmand have not typically been havens for al-Qaida.

“It’s been a relatively recent expansion to the south,” Jones said.

Afghan security officials say many of these foreign fighters filtering in are from Central Asia, and in many cases their affiliations are unknown. In the past, some of the groups have been affiliated with al-Qaida, but there have also been reports of some of these fighters pledging allegiance to the Islamic State.

One U.S. intelligence official sought to play down the menace from the new Qaida offshoot, calling it “a regional threat that is currently focusing on plotting attacks in Pakistan and establishing a presence in South Asia. Despite its safe haven, the group has not been seen conducting attacks against Afghan or Western targets in Afghanistan.”

The emergence of new Qaida training camps comes amid a widespread erosion in security in much of the country. “In the second half of 2015, the overall security situation in Afghanistan deteriorated, with an increase in effective insurgent attacks and higher ANDSF and Taliban casualties,” the Pentagon said in a report issued two weeks ago, using the initials for the Afghan National Defense and Security Forces.

Campbell told lawmakers that the Pakistani-based militancy, the Haqqani network, remains an important “facilitator” for al-Qaida in Afghanistan. The two groups, he said, share a goal of “expelling coalition forces, overthrowing the Afghan government, and re-establishing an extremist state.”

Rounding out the threats in Afghanistan, Campbell told lawmakers that the Islamic State’s branch in the country was rapidly drawing new fighters with its “virulent, extremist ideology.”

“While many jihadists still view al-Qaida as the moral foundation for global jihad, they view Daesh as its decisive arm of action,” he said, using another name for the Islamic State.

Citing a remark by the Afghan president, Ashraf Ghani, Campbell said, “If al-Qaida is Windows 1.0, then Daesh is Windows 7.0.”

Al-Qaida’s branch in the Indian subcontinent has also plotted attacks outside Afghanistan. Al-Qaida militants tried to hijack at least one Pakistan Navy frigate in September 2014 and to use it to attack United States Navy vessels on antiterrorism patrol in the northwestern Indian Ocean.

The raid on the navy vessel was foiled after a firefight. It turned out it was carried out in part by Pakistan Navy personnel who had been recruited by al-Qaida, Pakistani and U.S. officials said. The raid, in which 10 militants died, raised fears about terrorist infiltration of the military forces of Pakistan, which has nuclear weapons.

In May, the leader of the new Qaida branch posted a video claiming responsibility for the death of Avijit Roy, an atheist Bangladeshi-American blogger who was killed on Feb. 26 by men with machetes as he was leaving a book fair in Dhaka, Bangladesh.

The new Qaida affiliate has suffered some setbacks. The group’s deputy leader was Ahmed Farouq, a U.S.-born militant who was apparently seen as a rising star in jihadi circles for some time. In a letter to Bin Laden in 2010, which became public during a terrorism trial in New York this year, a militant of the same name was singled out as having potential leadership potential.

But Farouq was killed, along with five other suspected leaders, in the same airstrike in January that also mistakenly killed a U.S. aid worker, Warren Weinstein, and an Italian hostage.

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