Editor's note: Julian E. Zelizer is a professor of history and public affairs at Princeton University. He is the author of "Jimmy Carter," published by Times Books, and editor of a book assessing former President George W. Bush's administration, published by Princeton University Press.
(CNN) -- Republicans are divided over what to do about the defense budget. Secretary of Defense Robert Gates wants to reduce it by $78 billion over the next five years.
In his State of the Union address, President Barack Obama reminded Congress that Gates had agreed to cut out billions that "he and his generals believe our military can do without."
Some Republicans have acted reflexively, insisting on no cuts to the military budget. Howard McKeon, chairman of the House Armed Services Committee and an establishment Republican, said: "I cannot say it strongly enough: I will not support any measures that stress our forces and jeopardize the lives of our men and women in uniform."
Other Republicans have joined him. Sarah Palin has repeatedly stated that military spending should be off the table when it comes to deficit reduction. "The administration," Palin proclaimed last June, "may be willing to cut defense spending, but it's increasing it everywhere else. I think we should do it the other way round: Cut spending in other departments, apart from defense. We should not be cutting corners on our national security."
But some Republicans, primarily those associated with the Tea Party, have started to push back against their colleagues. Former House Majority Leader Richard Armey, who has worked closely with the leadership of the Tea Party Movement, told The New York Times, "A lot of people say if you cut defense, you're demonstrating less than a full commitment to our nation's security -- and that's baloney." House Speaker John Boehner and House Majority Leader Eric Cantor have signaled they are willing to consider the Pentagon's budget in discussions.
For many Republicans, the sound of conservatives calling for a smaller national security establishment seems to be sacrilege. After all, this is the party of Ronald Reagan, and it has insisted since the 1980s that more defense spending is essential to protect the nation. Whenever he was asked what he would do if it came down to a choice between defense and deficits, Reagan said: "I always said national security would come first, and the people applauded every time."
When a small group of House Republicans, led by former Georgia Rep. Bob Barr, opposed President Bill Clinton's push in 1995 and 1996 to strengthen the government in its capacity to pursue domestic terrorists following the Oklahoma City bombing, many members of the Republican establishment distanced themselves from Barr and his colleagues.
Yet another conservative tradition has supported restraint in military spending. Before the Cold War, some of the most prominent Republicans believed that too much spending on national security endangered civil liberties and produced excessive deficits.
Ohio Sen. Robert Taft, "Mr. Republican," spoke about the dangers of creating a leviathan state that quashed America's best democratic traditions. Even as Republicans like Taft abandoned their isolationism following World War II, they remained skeptical and critical of unlimited defense spending.
Dwight Eisenhower, one of the nation's greatest military heroes, was also a critic of excessive defense spending when he served as president from 1953 to 1961.
Americans often remember his famous farewell address, in which he warned of the creation of a "military-industrial complex" 50 years ago, as a warning about the potential for military leaders to make decisions without being accountable to civilians. But the speech was in large part about the dangers of an uncontrolled defense budget.
Eisenhower spent much of his presidency battling against hawkish Democrats who were pushing for higher spending on intercontinental ballistic missiles and other weaponry. Eisenhower, a fiscal conservative, believed that Democrats were being reckless in calling for these expenditures when the United States was well positioned against the Soviet Union.
In April 1953, his granddaughter Susan recently recalled in The Washington Post, Eisenhower told the American Society of Newspaper Editors: "This world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children. The cost of one modern heavy bomber is this: a modern brick school in more than 30 cities. It is two electric power plants, each serving a town of 60,000 population."
Indeed, when the Soviets sent the Sputnik satellite into space in October 1957, shocking many Americans, Eisenhower was furious that Democrats pounced on this moment as evidence he was not spending enough on defense. Eisenhower, who had secret U-2 satellites providing information that Democratic warnings about insufficient weaponry were false, couldn't believe what his opponents in Congress were doing.
While Senate Majority Leader Lyndon Johnson called Sputnik a disaster "comparable to Pearl Harbor," Eisenhower insisted limits must be put on how much the country spent on weapons. A frustrated Eisenhower privately said to legislators that the nation could "choke itself to death with military force as well as protect itself." He warned, "There is no defense of any country that busts its own economy." The president feared that the United States faced the risk of "destroying from within what you are trying to defend from without."
Those kinds of arguments quickly faded from the conservative lexicon. Most Republicans have embraced a firm and unequivocal stand in favor of higher defense spending. When Democrats have proposed reducing the defense budget since the 1960s, the GOP usually jumped and accused their opponents of being weak on national security.
But given the fiscal realities that the nation confronts, all forms of spending probably will be coming under budgetary scrutiny over the next few years. Republicans who are serious about deficit reduction must reconsider this lost conservative tradition and be willing to take a serious look at how much we spend on defense. Clearly, ample evidence shows it would be possible to make the budget more efficient and reduce many costs without posing risks to the nation.
Defense spending has not been a process in rational decision-making; it has been a political process often driven by partisan competition and interest group lobbying. If enough Republicans break with their party's conventional response, Congress could finally make significant process in developing a leaner and more effective budget for the Pentagon, one that revolves around national security needs rather than politics.
The opinions expressed in this commentary are solely those of Julian E. Zelizer.