Politicians will say it’s easy to cut the defense budget. Just wring out the waste, fraud and abuse and… voila! Unfortunately for them, there’s no line in the Pentagon’s budget labeled “waste, fraud and abuse.” And so, when cuts are made, they often wind up reducing investment in specific capabilities sorely needed by those in uniform.

It’s a real dilemma. Everyone wants to make the Pentagon more efficient, but no one wants to hurt the troops. Yet the latter is inevitable if the President and Congress continue down the path of drastic military spending cuts without changes elsewhere.

The American public tends to be okay with cutting defense budgets… until a crisis demands a military response. But when those crises arise after years of military belt-tightening, the nation winds up spending far more-in blood and treasure-than would’ve been necessary had Washington maintained stable, prudent funding levels in the run-up to the problem.

The consequences of cutting needed military capabilities are lagging indicators. We saw them in Iraq. Americans were outraged by the news that U.S. troops lacked body armor, leaving parents to send their kids home-bought armor in the early part of the war. They were outraged again when the Army took so long to acquire properly up-armored vehicles to combat the growing threat of roadside bombs.

But the lack of armor for troops and their vehicles was rooted in decisions made in Washington years before. The stress of war on the force and the lack of adequate protection were both perfectly predictable. Yet these foreseeable problems were ignored year after year during the late 1990s, as elected officials pressed to balance the federal budget in large part through military spending cuts.

Throughout the ’90s, the size of the Army was reduced by a full one-third. Yet the missions assigned to soldiers grew exponentially. After 9/11, that same stretched and smaller Army was tasked with manpower-heavy missions in Afghanistan and Iraq. One reason we hear of troops now on the fifth, sixth, and yes, seventh tours overseas is because the Army was cut too deeply in the 90s. The ground forces still haven’t recovered and President Obama is proposing to cut the number of soldiers and Marines in uniform to save money.

Oddly, the general public seems to be more outraged when Delta airlines charges an Army unit for checked baggage fees than when President Obama proposes slashing military spending by hundreds of billions of dollars while large numbers of military personnel remain in harm’s way-on his direct orders.

How can President Obama justify proposing drastic cuts in military spending when he has personally ordered a surge of 30,000 U.S. forces in Afghanistan, started a new military operation in Libya, doubled down on covert counterterrorism military operations inside of Yemen, kept over 1,200 National Guard troops at the U.S.-Mexico border, and sent U.S. forces to deliver humanitarian aid in Japan and Haiti?

A legitimate reason may be that taxpayers intuitively know there is money to be saved in such a large budget, and they’re right. But this would hold true for any government program. (Think Medicare fraud.) The big difference is that the military has already been contributing significant sums of money to deficit reduction, while the rest of government has not.

But perhaps the recent call for another $400 billion in defense spending cuts is just a sham. After all, the President proposed a review of the U.S. military’s roles and missions before he would approve this second round of cuts.

The presumption here is that the military will identify potentially outdated missions that it can afford to shed. Jettisoning such missions would allow for a proportional reduction in spending.

This is a worthy exercise, but it has two major flaws. The first is that only the President of the United States can truly alter U.S. foreign policy, not government bureaucrats. Many of the military’s commitments around the globe are an extension of foreign policy interests and agreements.

Mr. Obama, like all who have occupied the Oval Office since the end of the Cold War, has not reduced U.S. foreign policy commitments tasked to the military by one whit. Indeed, like all his post-Cold War predecessors, he has only increased the missions assigned to those in uniform.

Conducted honestly, a mission review could spark a useful debate over whether the Armed Forces can shed some non-core functions. For example, policymakers could consider whether to relieve U.S. Marines of responsibility for providing physical security at select naval bases (e.g., the submarine base at Kings Bay, Ga.) or certain embassies and consulates around the world.

The second flaw of this approach? While a document may recommend that the U.S. military should change, reduce, alter, or abandon some missions, actual task orders to the military are highly unlikely to change anytime soon. Does anyone truly believe an American president will not send U.S. forces to deliver disaster relief after the next catastrophic earthquake or tsunami just because it’s not recommended in a mission review report?

Unfortunately, the most likely outcome of any defense strategy review is: 1. nothing will change in reality for the men and women in uniform around the globe, and 2. the defense budget will still be cut precipitously.

The military is a tool of U.S. foreign policy. Slashing defense spending without any specific reductions in U.S. foreign policy commitments around the world is not only dangerous but more costly in the long run than maintaining stable defense budgets and military manpower levels.

A review of roles and missions will not change U.S. foreign policy; only the President can do that. Starving the military as part of a deficit reduction plan may end up costing taxpayers more in the future if it makes the country less safe, increases the risk of another terrorist attack, or grows the likelihood of drawing U.S. forces into yet another overseas mission.

The only responsible way to budget for defense is to identify the nation’s vital national interests, ask what is required to defend the nation and those interests, determine what military capabilities are required to do so, and then build a defense budget to meet those requirements.

Setting a goal of cutting defense by $400 billion and then trying to jam those cuts through while things on the ground and over the horizon remain unchanged can lead to only one result: the U.S. military will do more, less well.

That is a serious problem for the military given their mounting modernization needs. Not only must the Pentagon restore or upgrade equipment used heavily in Iraq and Afghanistan, it must also buy next-generation weapons, all while addressing the growing readiness problems across the force.

In April, a U.S. Navy cruiser failed its readiness inspection. It was declared not ready for sustained combat operations. It wasn’t the first time. Last year, two other Navy surface ships failed their readiness inspections. The Navy Times reports that a panel looking into the rising number of ship readiness failures had previously warned that “maintenance problems were spiraling out of control due to a lack of sailors and funding, as well as poor training and shifting priorities.”

Just last December, reports surfaced that all 22 U.S. Navy cruisers in service have cracks in their aluminum superstructure.

Twice this year already, two F/A-18C fighter jet engines caught on fire aboard aircraft carriers. Senior Navy officials have repeatedly identified keeping older F/A-18s in safe flying condition as “one of their most serious challenges.”

Cutting defense too fast or in the wrong areas is false economy. It will surely lead to a bigger bill later. But to do it at a time when readiness levels are dropping across the board, equipment needs are rising for every military service, and the force is still surging overseas is downright dangerous.

Mackenzie Eaglen, a member of the AOL Board of Contributors, is a former congressional staffer and defense analyst at the conservative Heritage Foundation.