Aside from Charlie Sheen or Chuck Hagel, who would want to be the next secretary of defense? The next occupant of the big office in the Pentagon’s E-ring will have the worst job in town because President Obama is doing to the Pentagon what he refuses to do to any other part of the executive branch: he’s taken a machete to its budget.

In February, Obama said that he wanted to take a scalpel, not a machete, to discretionary spending. And in his hyperpartisan budget speech on April 13, he made it clear that was true for every part of the federal government with one exception: the Pentagon. He demanded a new round of budget cuts worthy of the Queen of Hearts: “sentence first, verdict after.”

In the April 13 speech, President Obama claimed that Defense Secretary Bob Gates had already cut $400 billion from the Pentagon’s budget in ten years and said that another $400 billion in cuts should be added in that same period. It was the only real cut in federal spending Obama proposed.

He said, “Over the last two years, Secretary Gates has courageously taken on wasteful spending, saving $400 billion in current and future spending. I believe we can do that again. We need to not only eliminate waste and improve efficiency and effectiveness, but conduct a fundamental review of America’s missions, capabilities, and our role in a changing world. I intend to work with Secretary Gates and the Joint Chiefs on this review, and I will make specific decisions about spending after it’s complete.”

This is Obama’s “Queen of Hearts” theory of defense spending. He sets the amount of funding to be cut and then tells the Pentagon to do a study to justify it.

Begin with the questionable claim that $400 billion in “wasteful” spending (spread over ten years) has already been cut. We don’t know if the $400 billion was wasteful because the cuts were imposed before the Pentagon performed its “Quadrennial Defense Review,” a statutorily-required study which is supposed to measure our military forces against the threats they’re expected to meet and then provide a budget to accomplish the missions. Obama and Gates set the level of cuts and Gates then papered it over with a QDR that justified the predetermined cuts.

Now the president wants to take the machete to the Pentagon budget again. He wants the analysis to find an additional $400 billion to cut from the Pentagon budget in the same ten years and redefine our “role in a changing world.” It’s both necessary and proper to make the analysis the president proposed. But, once again, he’s set the amount to be cut before performing the essential threat analysis.

Since 2008, as George W. Bush’s defense secretary, Gates has derided the idea that we will ever have to fight another conventional war. He regularly condemns “next war-it is,” which he defined as “…the propensity of much of the defense establishment to be in favor of what might be needed in a future conflict.”

Gates, in forcing the abandonment of “next war-itis,” has imposed a change in American military thought and planning that served us well since World War II.

That change is revolutionary and dangerous. We will no longer plan for the future and invest in the tools of war we will foreseeably need. The cuts Obama and Gates have already made will result in a force that is shaped differently from the one we might need were an enemy to disagree with Dr. Gates’ belief that we won’t have to fight another conventional war. Or if American satellites were attacked in space. Or if we were to suffer the kind of cyber attacks that were made on Estonia, Kyrgyzstan, and Georgia by Putin’s Russia. Or if any number of other real threats were to be realized.

To borrow Obama’s phrase, let’s be perfectly clear. Our nation’s security and that of our allies is at risk because of the cuts that have already been made in the absence of a realistic analysis of the threats we face. We cannot afford another round of “hope and change” at the Pentagon. The armed services need a budget that enables them to meet and deter or defeat every serious threat.

Instead of allowing Obama and Gates’ successor to go about another round of random cuts, Republicans should do their own, aimed at producing a defense version of Paul Ryan’s “Roadmap” of last year. That study should begin with an analysis of the threats that must be met, derive from them the capabilities we need to meet the threats, and from those capabilities define the budget to ensure the Defense Department has the people and the assets to do the job.

Every Pentagon study I’ve seen or been involved with begins with a document called the “terms of reference” which defines the job to be done. Because Obama has announced the result he wants, his study will have terms of reference that are set to justify the cuts.

Because Gates’ first round of cuts was made without the essential analysis of the threats we face and the capabilities the Pentagon must have to meet them, any new study should not assume that they were correct.

The terms of reference for the Republican roadmap should be these.

First, the threats we expect the Pentagon to deter or defeat must be defined in clear terms. What are the intentions and capabilities of our enemies today, and what do we expect of them ten or twenty years in the future? How will we deal with terrorism and the nations that sponsor it? Cyber war (and cyber espionage) is one of the biggest threats we face. Our national security (and our economy) are increasingly dependent on satellites. But those satellites are orbiting undefended from kinetic or directed-energy attack. Potential adversaries such as China are already testing anti-satellite systems.

Once the threats are defined, they need to be compared to what assets — people, weapons, defensive systems, satellites and the rest — we have that are essential to deterring or defeating them. Among those systems and people will be assets we don’t need and old systems that need to be replaced. (And not only high-tech weapons. One of the Marine heroes who fought in Fallujah, Iraq, told me that in one gunfight, he had to shoot insurgents repeatedly — one man more than seven times — before the bad guy went down. Shouldn’t we be equipping the army and Marines with a better rifle?)

The Pentagon’s budget should be based on buying what it needs, cutting what it doesn’t and ensuring the means of deterring or defeating the threats we foresee for the next decade and beyond.

While doing their own defense review, Republicans should hold hearings to define what Obama’s vision for “America’s missions, capabilities, and our role in a changing world” really is. Call Secretary Gates in to testify on what the president means.

Does Obama mean that we will, as the Libya intervention indicates, devote our military power to conflicts in which we have no strategic interest? Does he mean, as his slow-rolling of ballistic missile defense shows, that we will not protect ourselves from that threat? Do Obama’s actions prove his conviction that America should not maintain its role as a superpower? Do Obama and Gates really believe that “next war-itis” is a mental disorder?

Everything we can derive from Obama’s actions compels that each of those questions must be answered in the positive. The president says he wants to “win” the future. How can that be done if we don’t first secure it?