By Adam Brookes
BBC News, Fort Bragg, North Carolina
On the flightline at Fort Bragg, North Carolina, there is an air of calm which belies the level of activity.
Will America's mission in Afghanistan be altered?
The unit based here, the 82nd Combat Aviation Brigade, will deploy to Afghanistan in a few weeks' time. Their helicopters will be loaded onto enormous cargo planes, some onto ships, and transplanted to Kandahar.
The soldiers of the 82nd CAB fly the army's lethal Apache gunships; but they also move casualties out of combat in Blackhawk helicopters and ship ammunition, water and troops in the workhorse Chinook aircraft. They support combat troops, providing fire and mobility. In military argot, they are "enablers".
And their deployment to southern Afghanistan tells us a deal about the conflict: that it is in the south - in Kandahar and Helmand - where the US military sees the greatest insurgent threat, and the greatest need for troops and mobility. The 116 helicopters of the 82nd CAB will, they hope, greatly extend Nato's reach.
They will be part of a substantial build-up of troops in the south. As part of Nato operations, they will come under the command of a Dutch general. And we found a sense among the 82nd that they are in for a bloody year.
"We're putting the squeeze on the bad guys," said Chief Warrant Officer Bert Shober.
"When we do that they tend to react, and so we will see soldiers injured or worse."
As the "Global War on Terror" fades from our lexicon, Mr Obama may set out a unifying idea to replace it
The violence in Afghanistan tends to increase through the spring and into the summer as the weather warms and formerly icebound roads become passable. It is CWO Shober's fourth deployment to a combat zone since 2001.
The commanding officer of the unit is Col Paul Bricker. His helicopters, he says, are the "coin of the realm" in Afghanistan, the only way to move fast enough across the rugged terrain.
But he insists it is not capturing terrain in the traditional sense he is interested in.
"The people are the prize," he says. "The people are the decisive terrain."
And much depends on the deployment of these "enablers", US Defence Secretary Robert Gates has said: pilots, medics, engineers, mechanics, linguists, administrators, intelligence officers - all of these, and more, must be found and deployed if the military effort in Afghanistan is to be reinvigorated.
And that is President Obama's aim.
President Obama, we are told, has for some days now been reading the review of Afghan strategy that he commissioned earlier this year.
Some version of that document is expected to make its way into a speech on Friday. Expect America's foreign policy "principals" - Secretary of State Hillary Clinton, National Security Adviser James Jones and others - to flank Mr Obama as he announces it.
Some of the broad outlines of a renewed strategy for the Afghan war are already clear:
The war will continue. The US will intensify its military effort for some time to come, and it will encourage Nato allies to do the same. The aim: to provide security within which an enhanced civilian and reconstruction effort can take root
There will be an overhaul of the Afghan effort - and a much greater emphasis on coordination and cooperation between countries and agencies
The president will argue that what happens inside Pakistan is central to the Afghan theatre. His strategy will try to draw together Afghanistan policy and Pakistan policy into a coherent whole
Afghan security forces will, one day, take over security operations and allow foreign forces to draw down
Other, non-Nato countries like China and Russia will be asked to support the effort, or at least not oppose it.
But we might expect President Obama to tell us more than just how the US intends to proceed in Afghanistan.
What, after seven years of operations, is the United States trying to achieve, and why?
As the "Global War on Terror" fades from our lexicon, Mr Obama may set out a unifying idea to replace it.
Many in Washington feel that strategy has, for seven years, been catastrophically absent, and each agency of government has blithely continued on its course without any reference to others.
Karin von Hippel at foreign policy think-tank the Center for Strategic and International Studies (CSIS) writes: "There has been no clarity as to how much US assistance has been directed at each country, what the overall strategy for each country is, nor what it is for the region as a whole."
One security source said that this will be the moment when Mr Obama "takes ownership" of the war.
Until now he has been able to "hide behind his strategy review". Not any more.
Chief Warrant Officer Bert Schober: 'We're putting the squeeze on the bad guys'
Officers at the Pentagon tell me they expect the total number of US and Nato troops deployed to hit 90,000 by the end of the summer. Not as big a commitment as Iraq, for sure, but still a very substantial commitment.
So is this a "surge"?
Military officers tell me "no". A surge, they say, implies a temporary increase in effort, followed by a winding down, as we have seen in Iraq.
But Mr Obama's vision for Afghanistan implies an increase in commitment to be sustained indefinitely, an important distinction.
Formulating the Pakistan element of the strategy has been the hardest part, I am told.
The Taleban and other insurgent groups, and al-Qaeda, continue to use Pakistani territory for their bases.
Until these sanctuaries are eliminated, and the recruiting of radicals curtailed, there would seem to be little hope for long-term stability in Afghanistan.
But how can the United States and its allies, like Britain, achieve this?
The US has few levers of power it can manipulate to change the security landscape in Pakistan, say security sources in Washington.
Without the wholehearted commitment of the Pakistani government and military, and a shared view of the problem, implementing a strategy to eliminate radicalism in Pakistan will be very difficult.
"Our best options are limited," says one. "How do we persuade the Pakistanis to own the fight?"
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