The two House committees that oversee the defense budget are likely to resist Rep. Barney Frank’s (D-Mass.) push to cut defense spending by 25 percent, although some reduction in military spending may be inevitable.

Rep. John Murtha (D-Pa.), the chairman of the House Appropriations Defense subcommittee, is already warning against a dramatic reduction in defense spending at a time when the military is fighting in Iraq and Afghanistan and facing daunting bills to repair or replace war-torn equipment.

“We also must re-establish our ground forces to be prepared for future deployments, but also as a credible deterrent to preventing war,” Murtha added.

A House Armed Services Committee aide, meanwhile, said panel members “would not consider a cut that sizable.” A 25 percent reduction would equate to a cut of around $150 billion in annual spending.

Democrats on the defense committees traditionally hold a more centrist view of military spending than do other members of their own caucus. Not only do they view themselves as protectors of the men and women in the armed forces, but many hail from districts in which defense companies are critical components of the local economy.

But the party as a whole, looking to burnish its national security credentials, has largely supported the increases in defense spending after Sept. 11, 2001, that were pushed for by President Bush.

The result has been a nearly twofold increase of the Pentagon’s budget over the last eight years. Defense spending now represents 54 percent of all the discretionary spending. When emergency supplemental appropriations bills that have largely paid for the wars in Iraq and Afghanistan are added to that, defense spending accounts for more that 57 percent of the total discretionary budget, according to the Center for Arms Control and Nonproliferation. At more than $600 billion, defense spending now amounts to 4 percent of the gross domestic product.

With the rise in the defense budget, the profits of defense companies also grew. For example, Lockheed Martin and General Dynamics have consistently posted double-digit quarterly earnings growth on record sales. Raytheon, meanwhile, reported a 43 percent increase in profit in its latest quarterly report.

But most experts agree that the upward trajectory of defense budgets cannot be maintained, and some trimming is inevitable. The question will be, by how much?

“I think we are not going to solve the deficit problem and be able to meet our requirements in Social Security and Medicaid unless we substantially reduce the military budget,” Frank told reporters last week.

Frank believes that the turmoil in the financial markets means that Congress needs to spend more in other areas and less on weapons system programs.

“I was teasing Jack Murtha and I said to him, ‘For the first time, somebody else has got a bill that’s almost as big as yours.’ We don’t need all these fancy new weapons. I think there needs to be additional review,” Frank told the New Bedford, Mass., Standard-Times.

But even Murtha has expressed willingness to trim the defense budget where he can.

“Our subcommittee reviews these weapons systems continually, and we eliminate those that are a waste of money,” Murtha told The Hill in a statement.

“We work to make sure that the department understands that they can’t have everything and that we must do what’s in the best interest of both the U.S. taxpayers and national security,” Murtha said.

Murtha, however, has been a strong supporter of procurement programs, and indicated recently that he would consider scaling back the planned personnel increase in the Army and Marine Corps to save money.

Personnel, operations and maintenance costs take up the highest percentage of the defense budget. These costs have also escalated with the wars in Iraq and Afghanistan, and would grow more when additional soldiers and Marines are added. Some of that new spending could be offset, however, if troops are withdrawn from Iraq.

By comparison, investment accounts — which include both procurement and research and development spending — make up 30 percent of the defense budget.

Some defense experts see Frank’s statements on the defense cuts as an opening salvo in an unavoidable debate over national security spending, rather than a hard and fast target he is shooting for.