The Pentagon's fiscal 2015 defense budget proposal will cost the Army another six combat units, shrinking the active force to 28 brigade combat teams by 2019.

Prior to Defense Secretary Chuck Hagel's Feb. 24 announcement, the Army was already on track to shrink to 490,000 soldiers. The force reduction will eliminate about a dozen BCTs, bringing the active force down to 32 BCTs by early 2016.

This latest round of budget cuts will force the Army to cut another four active BCTs as well as two combat aviation brigades, according to an Army official with knowledge of the plan.

The end strength announcement was part of the larger budget roll out that Congress still needs to sign off on before President Obama can approve it.

In addition to combat brigades, the Army would also have to cut up to 20,000 soldiers from combat support units, an Army source who asked to remain anonymous told Military.com.

The Army currently numbers just over 520,000 soldiers. Cutting the active force to a size of 440,000 to 450,000 would shrink the Army to the smallest it has been since before World War II.

Despite its reduced size, more than 10 years of war have made the Army effective at organizing potent force packages to respond to a wide range of battlefield challenges, the Army official said.

And with the war in Afghanistan drawing to a close, the Army is returning to a contingency-response mind-set.

"We are going to use a kind of a 2-2-2-1 contingency force, where you will have two armor BCTs, two Stryker BCTs, two infantry BCTs and an aviation brigade at the highest level of readiness," he said.

The Army's force reductions are a result of about $500 billion in a decade-long defense spending reduction mandated in the 2011 deficit-reduction legislation known as the Budget Control Act. Sequestration adds another $500 billion in automatic cuts.

Hagel warned that the Army would have to shrink to 420,000 soldiers if sequestration cuts are not rescinded by Congress.

The 2015 budget will also likely result in reserve forces being trimmed by about 30,000, including 20,000 from the Army National Guard and 10,000 from the Army Reserve by 2019. That would still leave more than a half million men and women, with 335,000 in the Guard and 195,000 in the Reserve component.

It's not a promising forecast, but it's not as bad as the massive drawdown the Army experienced at the end of the Cold War, said Army Lt. Gen. Joseph Martz, military deputy for budget.

In fact, the current reduction in Army end strength is far more orderly now than in the 1990s, when the service was forced to shed hundreds of thousands of soldiers over several years, including 100,000 soldiers in one year alone.

"It really harmed our personnel system," he said during a conference on the defense budget Tuesday at the Newseum in Washington, D.C. The event was hosted by Credit Suisse and McAleese & Associates, a Sterling, Va.-based consulting group. "You kind of just had to let people go."

--Associate Editor Brendan McGarry contributed to this story.

-- Matthew Cox can be reached at Matthew.Cox@monster.com.