Want to defend the status quo of deficit-ridden budgets? Set up a straw man to divert attention from social entitlements, where most federal spending goes.

This is exactly what the administration and congressional Democrats have done. The defense budget is their straw man. They insist that “defense be on the table” to reduce federal spending. They know that every dollar cut from the Department of Defense is one more they can pour into entitlements.

Their strategy is working. Neither Democratic nor Republican leadership has fully embraced serious reform of the nation’s unsustainable entitlement spending, yet both appear to accept the idea that defense must be cut. The reason is obvious: It’s politically easier to cut defense than entitlements.

Most Democrats have always wanted to cut defense. The question is why some Republicans would go along with that strategy, one that caves on a core conservative principle of maintaining a strong national defense without even beginning to address the real cause of the debt crisis: Runaway entitlement spending. Absent entitlement reform, Congress could eliminate the entire Department of Defense budget and still have crushing debt in the future.

Unless we reform Medicare, Medicaid and Social Security, the Congressional Budget Office forecasts, spending on just those three entitlements plus interest on the debt will consume all federal revenues by 2035. Nothing would be left for defense — or any other discretionary spending, for that matter.

Annual federal spending for these three entitlement programs accounts for 43.4 percent of all federal outlays (excluding interest). Defense outlays are less than half that amount accounting for just 21.1 percent of federal spending.

Most people wildly overestimate how much we spend on defense and greatly underestimate how much we spend on entitlements. Nearly half of all Americans surveyed in a recent poll mistakenly thought the largest area of spending is national defense. It’s not. Social Security, Medicare and other entitlements are. We spend just 4 percent of the gross domestic product, or GDP, on core defense (excluding overseas operations), well below our historical average.

Clearly, defense spending is not “out of control,” nor is it the cause of our rapidly ballooning debt. And yet lawmakers insist our security take a hit.

Defense cuts will have real negative consequences on the military. And they will only ratchet up defense spending over the long term. To accommodate cuts, the Pentagon will need to stretch out buying times for weapons and other equipment. That causes unit prices to soar, raising the ultimate tab for those procurements. Thus, the supposed “cutting” actions actually add upward pressure on long-term spending and debt. It’s a classic example of near-term pleasure causing long-term pain something politicians love.

The worst effects, though, will be on military readiness and morale. The Navy would have to shorten the notification time to sailors for upcoming rotations, which can hurt morale. There also could be a lack of funds to refurbish Humvees, which are heavily used in combat. This is no way to treat troops in wartime.

Defense cuts could adversely affect our military capability as well. The Air Force would need to ground some of its F-15 fleet, weakening the Air National Guards ability to patrol and provide U.S. air defense. Remember how important those planes were after Sept. 11. A second Virginia-class submarine and additional destroyer cannot be started, which will delay bringing those capabilities online and drive up costs. The Army likely would have to postpone working on a new ground-combat vehicle to improve protection for its soldiers. Production of new drones for use in Afghanistan will be pushed back. Training for soldiers and sailors will be scaled down, and shipyard repairs and maintenance will be canceled.

These real-world impacts in time of war do not even touch the source of the debt problem. It’s hard to avoid the conclusion that this is mainly all about symbolism and posturing and a huge distraction from the real problem.

Sure, savings can be found through greater efficiencies at the Department of Defense. But they should be put back into long-term funding for military modernization and force structure. The military services already have said their modernization accounts are underfunded by about $50 billion a year.

It would be one thing if providing for the “common defense” were some extraconstitutional luxury and thus rightly a target for budget cutting as a matter of principle. But that most definitely is not the case here. Defending the country is a core, enumerated, federal power mandated by the Constitution.

Entitlement spending, not defense, is the source of our nation’s debt problem. Those who ignore this fact aren’t serious about reducing the nation’s spiraling debt. Worse, they undermine the federal government’s ability to meet its constitutional obligation to defend the country.

Kim R. Holmes, a former assistant secretary of state, is a vice president at the Heritage Foundation