WASHINGTON - Faced with tight budgets at the end of two lengthy wars the Pentagon is proposing cuts that could reduce the Army to its lowest level since just before the U.S. entered World War II.

Budget proposals unveiled Monday by Defense Secretary Chuck Hagel would also eliminate the A-10 aircraft and the venerable U-2 spy plane.

Hagel announced the proposed cuts in a preview of the official Pentagon budget to be officially presented next week. He said the Army of tomorrow does not need "to conduct long and large stability operations."

"As we end our combat mission in Afghanistan, this will be the first budget to fully reflect the transition DoD is making after 13 years of war - the longest conflict in our nation's history," Hagel told reporters at a Pentagon briefing.

"Our recommendations favor a smaller and more capable force, putting a premium on rapidly deployable, self-sustaining platforms," Hagel said. That military force would still be able to respond to world crises by "maintaining its technological edge over all potential adversaries."

With less spending for military budgets and the continued prospect of an additional $500 billion in automatic spending cuts over the next decade, in recent years the Pentagon has been forced to make tough decisions about its force levels and current arsenal. The proposed budget for the 2015 fiscal year is $496 billion.

The most attention-grabbing proposal presented today would see the Army continue reducing its numbers from a projected 490,000 by 2015 to between 440,000 and 450,000 by 2017. That would make it the smallest active duty Army force since 1940, when it numbered 267,000. That number spiked dramatically to 1,460,000 in 1941 even before the U.S. entered World War Two.

Hagel acknowledged that the proposed force reductions do not come without risk, but "we can manage these anticipated risks under the president's budget plan." He said the smaller Army force would still be capable "of decisively defeating aggression in one major combat theater" while still able to support air and naval forces in another theater.

He cautioned that a return of steep automatic budget cuts in 2016 could lead to a further reduction in the Army's size to 420,000, which Hagel said "would be gambling that our military will not be required to respond to multiple major contingencies at the same time."

Joint Chiefs of Staff chairman Gen. Martin Dempsey told reporters that an Army force that size would be "too small."

"None of us are willing to take a gamble because at the end of the day it's our soldiers, sailors, airmen, Marines, Coast Guardsmen - America's sons and daughters - who will face tomorrow's challenges with the strategy, and resources that we develop today," Dempsey said.

In the years before 9/11, Army force levels stood at 480,000 before surging to a peak of 566,000 in 2007 at the height of the war in Iraq.

Hagel called the retirement of the fleet of A-10 Warthogs a "tough decision," as the low-flying aircraft has been used to great effect in supporting ground troops in combat situations in Afghanistan and Iraq.

But Hagel described the A-10 as "a 40-year-old, single-purpose airplane originally designed to kill enemy tanks on a Cold War battlefield. It cannot survive or operate effectively where there are more advanced aircraft."

The greater effectiveness of precision-guided munitions that can be dropped from other aircraft made the Warthog expendable, he said.

In a reversal, Hagel said the U-2 spy plane, in use since the 1950s, was also being retired. Just a few years ago it was deemed cheaper to operate than the unmanned Global Hawk aircraft. But with a reduction in operating costs for the more modern aircraft, the decision was made to proceed with the Global Hawk.

For now the Navy will be allowed to keep operating 11 aircraft carriers, though a decision will have to be made in two years about whether to continue with the scheduled refurbishing of the USS George Washington.

Hagel also announced that he was reducing the Navy's planned buy of 52 Littoral Combat Ships to 32 ships, partly out of concerns that those numbers would make up a big part of the Navy's 313-ship fleet.