Republicans may have won control of the House and picked up several seats in the Senate, but party leaders in both chambers will have to tread carefully to avoid a war between two entrenched factions of the GOP over defense spending.
Pro-defense Republicans already are clamoring to use their party's newfound legislative power to boost the Pentagon budget, pointing to the wear and tear on the military after nearly a decade of war and the need to hedge against a multitude of future threats.
Rep. Buck McKeon, R-Calif., who is expected to take the gavel of the House Armed Services Committee, has challenged the administration's plans for marginal annual growth in future defense budgets, arguing last week that the Pentagon must have enough funding "to address the challenges of today and the threats of tomorrow."
But fiscal hawks within the party are focusing like a laser on reducing the deficit, and they insist nothing should be off the table -- not even the defense budget, which makes up half of all federal discretionary spending but has long been considered immune to the kind of painful cuts that have targeted domestic programs.
Those deficit cutters, whose ranks will swell in the 112th Congress, "are going to have a lot of power because the Democrats are going to sit on the sidelines and watch us eat each other alive," said one former House GOP aide.
Underscoring the budget pressures is President Obama's own deficit commission. On Wednesday, the commission chairmen released a proposal that called for slashing $100 billion out of the Pentagon's budget by 2015.
Sen. Tom Coburn, R-Okla., perhaps the most ardent budget watchdog on Capitol Hill, seized on the chairmen's proposal Wednesday to declare "the greatest national security threat facing America today is our national debt and a Congress that has avoided tough choices for decades."
Indeed, Coburn, who is a member of the deficit commission, wrote a long memo to the chairmen in May calling on them to eliminate any wasteful or unnecessary spending in the Pentagon budget. As if foreshadowing upcoming battles over the budget and the deficit, he called Wednesday for a healthy and robust debate. "The fact is, if our country is going to survive for another generation, Congress has to make the tough choices now that will put us on a sustainable path," he said.
But the defense cuts in the proposal include several recommendations that would be dead on arrival at the House and Senate armed services committees, which are stocked with defense boosters on both sides of the aisle.
It includes cutting procurement by 15 percent and research and development by 10 percent, as well as freezing noncombat military and civilian pay and shuttering one-third of overseas bases.
The commission also wants to use $28 billion in Defense Department overhead cost savings projected for 2015 to pay down the deficit. But that proposal could set up a battle with Defense Secretary Robert Gates, who already has planned to reinvest that money in higher-priority defense accounts such as modernization.
Including that $28 billion and the recommended cuts to procurement and R&D, the total trimmed from military force structure and modernization accounts would come to $55 billion -- an amount that almost certainly will be unpalatable to the defense industry and its allies in Congress.
"History provides all too many examples where cuts to defense spending were followed by the rise of a threat that we were unprepared to meet," Marion Blakey, president and CEO of the Aerospace Industries Association, argued Wednesday. The recommendations, she added, would "undercut the capability of the nation's defense industrial base to design, build and support complex cutting-edge defense systems."
The commission's report isn't the first to take aim at the Pentagon budget. In June, the Sustainable Defense Task Force, composed of budget watchdogs and analysts, outlined several cost-cutting options that would yield $960 billion in savings in the Defense Department between 2011 and 2020.
Considering the politics involved in budget cutting, the deficit commission's report "is as realistic as the concept of deficit reduction itself," said Carl Conetta, a member of the task force and the co-director of the Project on Defense Alternatives.
A cut of that size, Conetta acknowledged, would cause a fair amount of pain within the Pentagon. But he added that it is "proportional to the level of pain that they're talking about across the board."
Budget hawks like Conetta and Coburn argue that the government cannot make a stab at deficit reduction without making difficult choices in the defense budget.
Republicans, with their history of solid support for the defense establishment, have more political freedom to make cuts at the Pentagon than their Democratic counterparts, who have tried to shed the label that their party is weak on defense.
"I think we have some street cred. We have been able to get away with a little bit more than they have," said the former GOP aide. "That's why Gates [a holdover from the Bush administration] has been able to do what he's been able to do in killing programs."
But to take those steps, there will almost certainly be a public clash within the Republican Party -- and it's unclear at this point who will prevail.
"There's going to be a hell of a fight," Conetta said. "I'm not willing to lay money yet on either side."