WASHINGTON (NYTIMES) - United States troops are set to leave Afghanistan no later than Sept 11, but the Pentagon, US spy agencies and Western allies are refining plans to deploy a less visible but still potent force in the region to prevent the country from again becoming a terrorist base.
Drawing on the hard lessons from President Barack Obama's decision a decade ago to withdraw US troops from Iraq - allowing the rise of the Islamic State three years later - the Pentagon is discussing with allies where to reposition forces, possibly to neighbouring Tajikistan, Kazakhstan and Uzbekistan, according to US officials.
Attack planes aboard aircraft carriers and long-range bombers flying from land bases along the Persian Gulf, Indian Ocean and even in the United States could strike insurgent fighters spotted by armed surveillance drones.
But there are risks.
Afghan commandos who have been providing the bulk of intelligence on insurgent threats could disintegrate after the US withdraws, leaving a large hole to fill.
Turkey, which has long had a direct relationship with Afghanistan in addition to its role in the Nato mission there, is leaving troops behind who could help the CIA collect intelligence on Al-Qaeda cells, officials note.
Still, planners at the military's Central Command in Tampa, Florida, and Joint Staff in Washington have been developing options to offset the loss of US combat boots on the ground, and President Joe Biden said on Wednesday that the revised approach would keep Al-Qaeda at bay.
"We will not take our eye off the terrorist threat," Mr Biden said in a televised address from the White House. "We will reorganise our counterterrorism capabilities and the substantial assets in the region to prevent reemergence of terrorist threat to our homeland."
But some former top commanders, as well as lawmakers from both parties, warned that absent the unrelenting pressure from US Special Operations forces and intelligence operatives in the country, Al-Qaeda could make a comeback in Taleban-dominated Afghanistan.
"As good as our intelligence and over-the-horizon capabilities are, there is no substitute for being there," Mr Joseph Maguire, a former top Navy SEAL commander who served as acting director of national intelligence in the Trump administration, said in an interview. "Our effectiveness in protecting our homeland will be significantly diminished."
'Off the books' forces
Even as military officials rushed to flesh out the details of Mr Biden's revised plan, top Defence Department officials and military commanders appear to have ruled out for now two other options that could be employed if this revised approach falls short.
More than 16,000 civilian contractors, including over 6,000 Americans, now provide security, logistics and other support in Afghanistan, according to recent figures compiled by the Pentagon.
Top military officials on Wednesday played down any significant role for civilian contractors in combating Al-Qaeda in Afghanistan, although some analysts say they could be used to train Afghan security forces.
Under Mr Biden's order, the United States is withdrawing 2,500 troops from Afghanistan, but the Pentagon actually has about 1,000 more troops on the ground there than it has publicly acknowledged.
The murky accounting results from some Special Operations forces having been put "off the books", Pentagon officials say, to include some elite Army Rangers, who work under both the Pentagon and the CIA while deployed to Afghanistan.
The Obama administration used similar sleights of hand under the bureaucratic term "force management levels", which resulted in more troops in war zones with little public oversight.
But Pentagon officials said they would not resort to those tactics to slip undisclosed troops into Afghanistan after the departure deadline, even though some analysts voiced skepticism.
"We are actively engaged in counterterrorism where every effort is made to minimise the 'troops' - the boots on the ground - and replace them with an invisible force that can achieve just as much," said Mr William M. Arkin, a longtime security analyst and author of a new book, The Generals Have No Clothes: The Untold Story of Our Endless Wars.
In his remarks, Mr Biden said that the United States would remain closely involved in the peace process between Kabul and the Taleban, and would continue to provide security assistance to Afghan security forces.
But the fear is that the US exit will lead to the collapse of a weak Afghan government and a deepening civil war with the Taleban, opening the door to a resurgence of Al-Qaeda.
Some former Special Operations commanders said the Pentagon should continue to train Afghan security forces as long as possible, even taking them out of the country for advanced, specialised, technical and leadership training, as US forces did with Iraqi troops in Jordan years ago.
But if Afghan security and intelligence forces falter drastically, that could significantly damage one of the US' best sources of intelligence on Al-Qaeda and other insurgents.