Many Republicans love Ron Paul’s limited-government philosophy but have problems with his foreign policy. This is understandable given the state of today’s Republican Party. But what many Republicans probably don’t realize is that Paul’s foreign policy is part of his limited-government philosophy — and it’s a crucially important part. If the American right does not begin to at least consider Paul’s foreign policy, it will continue to forfeit any hope of advancing a substantive conservatism.

As the Founders understood well, it is hard-to-impossible to preserve limited government at home while maintaining big government abroad. History and experience tell us that one always begets the other. This certainly rings true as we spend trillions of dollars on domestic programs that we match with trillions more overseas. The Founders’ talk of “entangling alliances” requiring “standing armies” was recognition of the inherent dangers of war — and especially permanent war. “Mr. Republican” Sen. Robert Taft would echo similar sentiments a century and a half later in his battles against New Deal liberals. President Dwight Eisenhower’s warning about the “military-industrial complex” reflected the same concerns within a 20th-century, post-WWII context.

Almost alone, Ron Paul today carries on this important Republican tradition. Like every other conservative, Paul believes that America must have a strong national defense — he simply believes we can no longer afford our current irrational offense.

Unfortunately, unlimited Pentagon spending remains the big government too many Republicans still love. During the Reagan era, when we were fighting a global superpower that possessed thousands of nuclear weapons, this made sense. It does not make sense anymore. Today, we are fighting individuals, or collections of individuals, with infinitely less military capabilities and no particular attachments to nation-states. Ask yourself this: What, exactly, does having thousands of troops stationed in Afghanistan do to prevent some sick individual from trying to blow up his underwear on an airplane? Just as important, ask this: Does having thousands of troops in places like Afghanistan make it less likely — or more likely — that some sick individual will try to blow up his underwear on an airplane? Our own military and CIA intelligence tells us that our overseas wars actually encourage terrorist attacks. A majority of the members of the U.S. military agree, or as a Pew Research Poll of Iraq and Afghanistan veterans published in October revealed: “About half (51 percent) of post-9/11 veterans say that the use of military force to fight terrorism creates hatred that breeds more terrorism.”

These are basic questions that Americans desperately need to ask. Ron Paul is asking them. The other candidates don’t even consider them questions.

Which brings us to conservatism’s fate. Want to know why Paul is the only GOP presidential candidate who has proposed substantive spending cuts — $1 trillion in the first year? It’s because only Paul addresses Pentagon spending, the largest portion of our budget after entitlements. What the Republican candidates who eschew Paul’s foreign policy are essentially saying is this: We support limited government in theory but in practice it’s simply too dangerous. Paul continues to make the same argument that former Chairman of the Joints Chief of Staff Mike Mullen has made: that our debt is the greatest threat to our national security. Newt Gingrich, Mitt Romney and the other GOP candidates do not see our debt as a similar threat — if they did, they would be calling for bigger spending cuts.

As for national security concerns, Paul’s $1 trillion in cuts still allows for a defense budget four times greater than China’s and larger than even President George W. Bush’s 2005 defense budget. This is how drastically Pentagon spending — along with all government spending — has grown under President Obama. Cries from the GOP field that Obama is “weakening” our defense with “cuts” mirrors liberal shrieking about conservatives hurting the poor or seniors by reforming welfare or entitlements (just ask Paul Ryan).

Big-government advocates always claim that any changes or reductions in the status quo would be catastrophic. Conservatives always argue that not only can we no longer afford such spending, but that reducing big government will be better for all parties involved in the long run. Republicans can remain doubtful about whether Paul’s foreign policies will actually make us safer (they will, if our own intelligence and military members are to be believed). But they cannot doubt that Paul’s foreign policy addresses a cost we can no longer afford (our current foreign policy and related spending costs about $1.2 trillion annually, roughly our entire deficit).

The only GOP candidate offering the kind of cuts the tea party has said it desires is Ron Paul. If Paul’s foreign policy makes him beyond the pale politically, then the tea party’s desires become academic. This is a matter of fact and basic math, or as Rush Limbaugh explained in October:

Ron Paul is about to show the Republican presidential field what a serious fiscal reform plan looks like. He is going to propose $1 trillion in real spending cuts. What this indicates is something, folks, that we have got to face, if we are serious about this. Fooling around the margins isn’t going to get it done. A 2% tax cut here, or a 3% tax variation over there is not going to fix what’s wrong. Genuine, big spending cuts are the only thing that is going to bring us back …

Limbaugh added that Ron Paul’s plan was the only serious conservative budget even proposed. Rush said such ideas aren’t even original to Paul: “Now, these are not really Ron Paul’s ideas. We’ve long been an advocate of this … But nobody on our side has ever seriously proposed this and Ron Paul is going to. We have called for everything that Paul is suggesting. He will be the first candidate to actually do so.”

To disqualify Paul because of his foreign policy views is to also disqualify any chance of actual spending cuts. Until conservatives learn this lesson and begin to apply their limited-government philosophy comprehensively, conservatism itself will largely remain a moot point.

Jack Hunter writes at the “Paulitical Ticker,” where he is the official Ron Paul 2012 campaign blogger.