The Pentagon's coming budget request will reduce overall troop strength as the combat mission in Afghanistan recedes and budget restraint dominates the conversation in Washington, top defense officials said Monday.

For the first time in more than a decade, the Defense Department is presenting a budget to Congress that isn't a "war-footing" request, Secretary of Defense Chuck Hagel said. “It's a defining budget because it starts to reset, reshape … rebalance, redefine our enterprise for the future.”

The formal fiscal 2015 budget request is set to be filed on March 4, but Hagel and Joint Chiefs of Staff Chairman Gen. Martin Dempsey gave notice that no service would be spared from the Pentagon's reductions in spending.

The Army, which has 520,000 active duty soldiers, is projected to be reduced by even more than previously projected, to a size of between 440,000 and 450,000 soldiers - the lowest level of Army troop strength since before the U.S. entered World War II.

The Air Force would retire the U-2 spy plane and its A-10 Warthog fleet; the Navy would reduce the number of littoral combat ships in its future complement; and the Marines would reduce their size from 190,000 to 182,000, then to 175,000 if further budget cuts are not averted in fiscal 2016.

And for the personnel who do remain the military, the Pentagon is proposing changes to their benefits, including slowing the growth of tax-free housing allowances and discontinuing reimbursement for renter’s insurance. Further, co-pays and deductibles in the Tricare health insurance program afforded to retirees and some active duty family members would rise.

The Pentagon will also seek a reduction in contract spending, seek base closures in Europe and reduce overall troop strength as it “favor[s] a smaller and more capable force, putting a premium on rapidly deployable, self-sustaining platforms that can defeat more technologically advanced adversaries,” Hagel said.

In a budget request characterized by slashed spending figures, programs and troop numbers, one of the few growth areas projected by the Pentagon was in special operations forces personnel, from roughly 66,000 today to 69,700 over the next few years.

Under the Bipartisan Budget Act hashed out by Rep. Paul Ryan, R-Wis., and Sen. Patty Murray, D-Wash., the Pentagon's budget is limited by law to $496 billion in fiscal 2015, some $45 billion less than was requested by the president's budget last year.

Automatic cuts sliced $37 billion from the Pentagon's budget last fiscal year, part of the "sequestration" that was triggered when Congress failed to come to a long-term agreement on deficit reduction. This was on top of a 10-year plan to cut a further $487 billion from the Defense Department, as agreed to in the Budget Control Act.

Still, Monday’s budget preview by Hagel and Dempsey showed that the Pentagon is requesting $115 billion more over the next five years than sequestration caps would currently allow.

“The reason we are requesting this increase over sequestration levels is because the president and I would never recommend a budget that compromises out national security,” Hagel said, warning that the steep cuts could lead to a “hollow force.”

Hagel said the Pentagon was faced with a difficult decision in making the cuts he and Dempsey will soon present to Congress – make “modest adjustments” now or make even more painful decisions later.

“The recommendations I have described will help bring our military into balance over the next decade and responsibly position us for an era of both strategic and fiscal uncertainty,” he said.