Updated 4:45 p.m.

The Air Force is preparing to trim hundreds of aircraft from its aging fleet in order to meet an Obama administration austerity order. The move will strike many Air Force supporters as ironic. Because just as the fleet is set to shrink, Defense Secretary Leon Panetta is getting ready to argue, at least implicitly, that the country needs it more than ever.

Danger Room has learned that around 200 airplanes, mostly older models, will eventually be retired without replacement. That represents about a 5 percent reduction in the overall fleet of about 4,000 aircraft. Exactly which planes will go is unclear. But under any scenario, the positions of thousands of airmen who fly and maintain those planes will be phased out. The majority of those airmen will be reservists and Air National Guardsmen.

On Thursday, Leon Panetta will announce a new American defense strategy – one that military observers say will stress the centrality of the Pacific region, and by extension, the U.S. Air Force and Navy. But these services will not be exempt from the new pressure in Washington to rein in federal spending. In addition to scrapping the older planes, Danger Room is hearing that the Pentagon is still considering delays to the Air Force's planned next-(next-)generation bomber, a program unveiled by former Defense Secretary Robert Gates just a year ago. Although the F-35 Joint Strike Fighter family of jets is the most expensive defense program in human history, it's expected to take relatively minor cuts, such as further delays, not necessarily major budgetary hits, military and Capitol Hill sources say.

Much remains unsettled ahead of the formal announcement of next year's defense budget request, scheduled for later this month. That's when Panetta and Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, will lay out what hardware gets cut under a plan to cut defense spending by $450 billion over the next decade. But "the Air Force will be proposing substantial force reductions, amounting to a couple hundred aircraft," a senior military official who requested anonymity tells Danger Room.

The Pentagon leadership has been trying to tether the budget cuts to a shift in the U.S.'s overall defense posture, predicated on the end of the Iraq War and the beginning of the end of the Afghanistan War. Land wars are out; Asia and the Western Pacific are in. Panetta and Dempsey are expected to make that case at a Thursday Pentagon press conference.

Except that if Asia and the Western Pacific are the new U.S. defense hotspots, then the U.S. will lean heavily on the Air Force (and, of course, the Navy) – while reducing its air fleet. Gen. Philip Breedlove, the Air Force's second in command, warned in July that the budget cuts could jeopardize the Navy and Air Force's much-hyped plan for joint warfare in the Pacific, known as AirSea Battle.

The apparent tension between strategy and cash has the Air Force's advocates indicating they'll resist the cuts.

"The nation is best served if it modernizes its Air Force and its Navy. The big question is whether the money will flow to support the stated strategy," ret. Lt. Gen. Michael Dunn, president of the Air Force Association, tells Danger Room. "We will argue that the secretary is right about what he says about the strategy."

In other words, Panetta is right about prioritizing Asia, so he needs to give the Air Force the cash necessary to prioritize it – not cut the air fleet. The Air Force Association has plenty of friends on Capitol Hill who will be receptive to that message.

Panetta and Dempsey are not expected to specify which planes, ships, guns or trucks get cut in their Thursday press conference; that's for the unveiling of the budget later this month. One close observer of Pentagon budgets warns that older bombers, like the B-1, might get slashed even before the new bomber is ready, because they're expensive gas guzzlers. Older manned fighter jets might take a hit, as the Pentagon probably won't cut its drone fleet or significantly pare back its F-22s and F-35s. The Air Force's ancient fleet of Eisenhower- and Kennedy-era tankers are so central to the military's actions around the globe that it's hard to imagine any getting phased out until replacements arrive.

The Air Force won't be the only service in for budgetary pain. Danger Room is also hearing that the Army is likely to lose more soldiers from its active-duty ranks than it wants. (Irony: the Pentagon waits to cut the Air Force after fighting a decade of land wars; and the Army's reward for surviving them is major shrinkage.) Cuts to the Navy and the Marine Corps are likely as well, and there will probably be some restructuring of the military's expensive pension system as well.

But even though the cuts aren't finalized yet, the Air Force is already bracing for them. And its allies, armed with the Asia-first strategy, won't take them lying down.

"Plans with Iran would rely predominantly on air and naval power. Libya was mostly air power, and the Pacific is clearly a naval and air arena," says Dunn. "I would note that my naval friends say the Pacific is 75 percent covered by water – but it's 100 percent covered by air."

Update, 4:45 p.m.: According to Inside Defense, the Army shrinkage we heard about isn't just real, it's serious. Over the next five years, the Army will lose nearly 100,000 active duty soldiers, going to an "end-strength" of 480,000 to 490,000. That's a significantly deeper manpower cut than the Army expected – it was slated to go down to 520,000 soldiers – at a faster clip: the reductions Gates announced last year started in 2015. The Marines, too, will shrink from 202,000 to 181,000 leathernecks, which is a few thousand Marines fewer than Gates envisioned; they'll return to being more of a sea-based service instead of a de facto second Army.

This moment was coming. At last year's big Army convention in D.C., Gen. Raymond Odierno, the chief of staff, warned that budget cuts would probably shrink the Army to a smaller size than he's comfortable with. Odierno also said that his priority was to preserve a capable, deployable Army that's well-trained to win wars, even if it's relatively small. But make no mistake: Odierno does not want this.

If you're wondering why the Army (and Marines) will shrink so much, the reason is the impending Asia pivot – which Obama himself will visit the Pentagon tomorrow to announce. Not only will Obama, Panetta and Dempsey say that land wars are passe, they're expected to abandon a formal planning posture committing the military to prepare for two major simultaneous wars. Most experts think the posture is archaic, but the Army spent most of the last decade fighting two simultaneous ground wars – and, the Army is quick to remind, had to add tens of thousands more soldiers to do so.

For their part, the Air Force and Navy are quick to remind people that it's cheaper and faster to bring up new soldiers in an emergency than it is to build and deploy new planes and ships. True, but it may not be that simple. The diminishment of the Army in both size and prestige carries the prospect of losing battle-experienced career officers, testing the Army's ability to retain the hard lessons of Iraq and Afghanistan for the next time the U.S. faces unexpected land wars. Your move, Gen. Odierno.

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