Rick Santorum and Ron Paul finished in a close second and third in Tuesday night's Iowa caucuses. But they could scarcely be farther apart in their foreign policy visions, not to mention their views on the proper role of government — revealing a massive fracture in the Republican Party. If the trajectory of their careers in the last five years is any indication, Paul's ideas are gaining influence, while Santorum appears to be one of the last of the completely unrepentant Bush-era Republicans. Paul was never going to be the nominee this year, but the party continues to move gradually in his direction.  

Paul was overtaken Tuesday by Santorum's late surge, but the Texas libertarian's showing in Iowa represented more than a doubling of his 2008 result, and his numbers were boosted by strong backing from independents and young voters. Unlike Santorum, Paul has a significant campaign presence in other early states, and will still be reasonably competitive in the weeks to come. Considering the amount of time Santorum spent in Iowa over the last several months (by far more than any other candidate), and the presence of a natural constituency of social conservatives and evangelicals he should have been able to win over, the former Pennsylvania senator's result is not all that impressive compared to Mike Huckabee's four years ago.

Santorum's presidential campaign is an exercise in continuing to deny that the public has already repudiated the foreign policy he promotes.

Santorum was a two-term senator who chose the worst year of the Iraq war — 2006 — to make his re-election a referendum on the most unpopular and aggressive aspects of President Bush's foreign policy. Santorum was clobbered by Democrat Bob Casey, and his re-election bid reflected the political fortunes of the party as a whole in 2006. The GOP lost control of both houses of Congress, in no small part because of growing public opposition to the war in Iraq and the reckless administration that launched it. Like the rest of the party, Santorum has not yet learned the lesson from those midterms: He and the GOP had been wrong on these issues. Santorum's presidential campaign is, in some respects, an exercise in continuing to deny that the public has already repudiated the foreign policy he promotes.

Indeed, Santorum's politics are nearly the essence of Bushism. Paul represents the full-throated rejection of the same. If Paul is well-known for his strong anti-war views and sharp criticisms of U.S. interference abroad, Santorum has been no less outspoken in favor of ever more intrusive and interventionist policies. While Paul has been the lone voice warning against a rush to war against Iran, Santorum demands a more combative Iran policy. Santorum's campaign rhetoric reads as if it were a caricature of neoconservatism. He believes that the U.S. is at war with "Islamic fascism," which he sees a global threat on par with 20th century totalitarianism. He insists that we must promote democracy, but we must never allow democratic elections to empower Islamists. Oh, and terrorists hate us because we are free. U.S. policies have nothing to do with it.

Santorum and Paul have also clashed over the size and scope of the state at home, as Santorum has regularly defended the PATRIOT Act, indefinite detention and torture of terrorist suspects, and illegal surveillance by the government. Santorum is also a strong believer in an activist, centralized government promoting morality nationwide. Paul, on the other hand, is a fierce critic of any federal government activity not explicitly authorized by the Constitution. The largest expansion of the welfare state in a generation received Santorum's backing, while Paul has been an inflexible, stalwart opponent of the expansion of government.  

Paul and Santorum represent the two poles of Republican foreign policy today, and their visions are completely incompatible with one another. On one side, Paul advocates for a libertarian and non-interventionist position that traces its origins to the pre-WWI foreign policy tradition of the republic. On the other, Santorum aligns himself with a fusion of "hard Wilsonian" internationalism and nostalgic rhetoric that frames every issue in terms of a Churchillian struggle against massive foreign threats. Despite sharing the same nominal partisan affiliation, the gap between Paul and Santorum is far larger than the differences between the rest of the Republican field and President Obama. At the same time, the former senator's combination of interventionism and "big-government conservatism" actually serves to make one of Paul's central arguments for him, which is that support for government activism abroad tends to encourage the same at home.