A crusader image doesn’t fit Robert Gates—the archetypal Midwesterner whose eyes and lips barely stir even in his most animated moments—but he is on a crusade to cut military spending. Well, it’s not exactly to cut it; for the moment, he is seeking to reduce bloating and waste and to use those funds to maintain muscle. His proposed savings from fat are modest (around $15 billion in an over $700 billion budget for next year). He’s also trying to prevent Congress from tacking on billions in unnecessary weapons systems. For now, Gates’ crusade is really much less about money and much more about principles: Reduce military expenditures to lower federal deficits and help build the kind of vibrant economy necessary for military power. Take as much of the cuts as possible out of waste and “political” expenditures and put that toward preserving firepower. In sum, the Pentagon has to make tough decisions to help itself and the nation’s economy.

Mr. Gates has been invoking the famous words and warnings of former general and President Eisenhower to enhance his crusade. That name may cause goose bumps for my generation.

The defense secretary has the best facts and the best arguments on his side. He’s also playing the politics of the occasion just right—starting small, small enough just to make the point without rousing the lions of the military-industrial complex. Alas, it only takes the bare scent of challenge to rouse them, and they’re roaring. And with just a few days to go before the Pentagon budget is reported out by the House and Senate Armed Services committees, it looks as if Mr. Gates’ noble crusade will garner little support on Capitol Hill. No matter how just the cause, Washington can’t make a tough decision. It is broke financially and broken politically. The ding-dongers or tea baggers or whatever they are, are certainly right about that—but even they don’t want to cut military outlays.

Mr. Gates has been invoking the famous words and warnings of former general and President Eisenhower to enhance his crusade. That name may cause goose bumps for my generation, but probably leaves cold most members of Congress, who think Ronald Reagan commanded the Allied forces during World War II. Nonetheless, Eisenhower is the right model.

Gates’ main takeaway from the former five-star general is this: “The United States…could only be as militarily strong as it was economically dynamic and fiscally sound.” He also deploys two crushing quotes from the former president. The first one regards Eisenhower’s classic warning about the military-industrial complex: “This conjunction of an immense military establishment and a large arms industry is new in the American experience… We recognize the imperative need for this development. Yet we must not fail to comprehend its grave implications.” This is a warning about ever higher and unjustified spending. The second one is Eisenhower’s punch line: “We must not destroy from within what we are trying to defend from without.” In other words, the U.S. economy must come first.

The defense secretary hauls out a truckload of examples of waste and mismanagement that can be safely cut. Two decades after the end of the Cold War, we still have more than 40 generals, or their equivalents, based on the European continent, and one can find as many as 30 layers between Gates and an action officer. To no one’s surprise, Gates notes that overhead accounts for roughly 40 percent of the Defense budget. As far as weapons spending is concerned, Gates insists that the Air Force already has more than enough C-17 cargo planes, despite Congressional insistence that production lines keep belching unneeded aircrafts. He is similarly trying to prevent a Congressional mandate to develop a second, or alternative, engine for the F-35 Joint Strike Fighter for $3 billion, when the existing one is perfectly satisfactory. These Congressional maneuverings are all about jobs in the districts and states and NOT about national security. Of course, Gates also wants to curb military health-care costs, which now total $50 billion and rising. His band aid would be to increase premiums for retired military. No one is betting on this.

Mostly, Congress is trying to ignore the defense secretary’s crusade. Most of the leadership there concedes privately that the Pentagon boss is absolutely correct in what he’s trying to do. They fully understand that American military power cannot survive the United States being a huge debtor nation. They know military cuts must come, along with slashes in other areas. But when vote comes to vote, it’s always “not in my backyard.”

About the most sympathetic statement Gates has received from a Congressional power broker came from Senator Carl Levin. The chairman of the Senate Armed Services Committee gave Gates “high grades for courage” and insisted Congress would “like to be helpful.” Meantime, the relevant committees have already voted against some of Gates' recommendations. For example, the House Armed Services Committee approved a 1.9 percent military pay increase—0.5 percent more than Gates sought, though military pay increases now exceed that of comparable civilian jobs. Two of that committee’s subcommittees also approved $485 million to continue the second engine program for the F-35.

Nonetheless, this highly unlikely crusader charges on. Gates is receiving modest press attention. Pushback is beginning from the military-industrial complex and conservative intellectuals who are pumping for increases in spending, not decreases. In fact, Mr. Gates is keeping his crusade alive almost all by himself—if you don’t count New York Times editorials.

The White House is notably absent from the public arena on this one, though Mr. Gates warns Congress of an Obama veto of the Pentagon bill if Gates’ recommendations are flouted. But no one in Congress has been seen trembling at this threat.

Leslie H. Gelb, a former New York Times columnist and senior government official, is author of Power Rules: How Common Sense Can Rescue American Foreign Policy (HarperCollins 2009), a book that shows how to think about and use power in the 21st century. He is president emeritus of the Council on Foreign Relations.