It's an exciting time to be a policymaker in the Republican Party.

Even as the war of words between New Jersey governor Chris Christie and U.S. Senator Rand Paul of Kentucky moved last week to a food fight over domestic spending, a

view is already crystallizing that one of the major intraparty battles between now and 2016 will be between national-security hawks like Christie and more isolationist libertarians like Paul. Although the war of policy ideas is intensifying within the Republican Party, the fight over foreign policy is more complex than meets the eye, and the battle lines are far from settled. ="#ixzz2axdawbfq">

The coming debate over Republican foreign policy involves not one binary fight, but rather three separate battles that scramble both the dove/hawk meme and the traditional left/right divide in American politics. Christie and Paul are currently fighting in just one of those battles, whereas the fight to determine the GOP's foreign policy will be an even wider free-for-all on turf that Christie himself likely hasn't given much thought.

If former secretary of state Hillary Rodham Clinton runs for and wins the Democratic nomination in 2016 as expected, Clinton's foreign policy will largely be continuous with the Obama administration’s approach—a mix of cautious, multilateral, humanitarian interventionism. The right seems the likelier laboratory for new approaches to U.S. foreign policy.

Reporter Dan Balz notes in his upcoming book Collision 2012 that when pressed to run for president last year, Christie admitted to his admirers, “I haven’t given any deep thought to foreign policy.” Christie's own views likely remain far from fully developed. Furthermore, because Paul has an incredibly difficult path to the GOP nomination (no matter what polls show today, twenty-eight months away from the Iowa caucuses), it might be a success merely to influence the ultimate course of future Republican thought by shifting the party's line in any one of the three fights, an outcome that seems quite plausible even if Christie himself winds up as the nominee.

Liberty versus security

When Christie spoke out late last month at Colorado's Aspen Institute against 'esoteric, intellectual debates' concerning the tradeoffs between liberty and security in U.S. policy, launching a rhetorical arrow at Paul, it was immediately interpreted as the first major shot of the pre-primary campaign in advance of the 2014 Congressional midterm elections and the 2016 Republican nominating process.

The fight over the appropriate balance between liberty and security is a debate already cross-pollinates a parallel fight within Republican circles over whether the party should adopt a more libertarian stance on domestic policies as well as on anti-terrorism issues, such as the ongoing relevance of the USA PATRIOT Act and the creeping nature of the National Security Agency's internet-surveillance programs. The next presidential election will be fully a decade and a half after the 2001 terrorist attacks, voters on both sides of the spectrum will still be weary of foreign misadventures, and many grassroots conservatives instinctively mistrust the Obama administration's embrace of security tactics like PRISM. So it won't be enough for national security Republicans to run on a platform of 'a noun, a verb and 9/11.'

Paul is an outspoken critic of encroaching infringements against civil liberties, alleging the unconstitutionality of PRISM as well as the PATRIOT Act. Fellow senator Ted Cruz of Texas, also a potential 2016 aspirant, also echoed Paul in many of those concerns, and that's one of the reasons that Arizona senator John McCain referred to both Paul and Cruz as 'wacko birds' earlier this summer.

Other Republican contenders are less strident on PRISM, joining McCain and Christie on the pro-'security' end of the debate. Wisconsin congressman and 2012 vice presidential nominee Paul Ryan last week opposed Michigan congressman Justin Amash's nearly successful bipartisan amendment to defund spending on domestic surveillance. Freshman senator Marco Rubio of Florida shrugged off concerns over PRISM as a necessarily evil in the fight against Islamic terrorists: "It's just the reality. We have to deal with it." But Rubio also joined Cruz in supporting Paul's iconic 13-hour Senate filibuster earlier this year protesting the Obama administration's drone strikes, particularly those strikes that target U.S. citizens abroad. So on these issues, as in many fights, there’s a spectrum, not two poles.

Unilateralists versus multilateralists

The second fight pits unilateralism against multilateralism—to what degree should the United States work through the channels of international law to effect foreign-policy goals?

While the conventional wisdom is that Republicans tend toward unilateralism and Democrats tend toward multilateralism, the reality is more complex. Both parties, especially once in power, have taken a pragmatic view of the benefits and drawbacks of multilateral institutions. It was under Democratic president Bill Clinton that the United States sidestepped the United Nations Security Council in mobilizing its NATO allies in 1999 to liberate Kosovo from Serbian aggression, and Republican president George W. Bush respected it enough to seek action under the existing Security Council resolutions to justify the 2003 U.S.-led invasion of Iraq,

The Republican Party is certainly home to plenty of unapologetic unilateralists, such as former U.S. ambassador John Bolton, but it also has its share of multilateralist voices as well, including Robert Zoellick, the former president of the World Bank, who could well become Secretary of State in a future Republican administration. It's hard, despite his hawkish campaign-trail rhetoric, to imagine that a potential Mitt Romney administration would have leaned more toward Bolton than Zoellick.

As Republicans look to 2016, it seems likely, based on past anti-U.N. sentiment, that Paul will be among the most strident voices opposing U.N. influence. There's really no basis to know where Christie or Rubio, who last month introduced a bill in the Senate tying U.S. funding for the United Nations to reform, will ultimately land in this debate—they could wind up closer to Paul or closer to multilateralists like Zoellick.

Liberals versus realists

The third and final debate lies along classic international relations theory—liberals versus realists. Bush-era neoconservatives and Clinton- and Obama-era liberal interventionists both share enthusiasm for using U.S. military intervention as a strategic tool, whether the purpose be reshaping a more democratic Middle East or preventing an imminent humanitarian crisis. There is a certain affinity among Democratic realists like former Obama national-security adviser Tom Donilon, Republicans like former defense secretary Robert Gates, and realists from previous Republican administrations, like former secretaries of state James Baker and Colin Powell and former national-security adviser Brent Scowcroft. Even though they might not embrace Paul, who sometimes seems like the second coming of the 1950s isolationism of Ohio senator Robert Taft, they share much in common with Paul and his libertarian allies, primarily a sensitivity to the dangers of military overreach.

McCain and Cruz have taken a highly neoconservative position in urging a more aggressive posture toward Syria, even advocating U.S. military invasion to eliminate the chemical weapons stockpiles of strongman Bashar al-Assad. But other longtime neocon voices, like former U.S. House speaker Newt Gingrich is not only retreating from Syrian intervention, but also admitting that the U.S. capability to export democracy is extremely limited. Realists would simply argue that the United States simply has no national interest in Syria that's worth deploying U.S. troops into the middle of the Syrian morass.

We still don't know where Christie's ultimate views on international-relations theory lie because that's not exactly one of the key concerns of a U.S. state governor. But given that the battle for the future of Republican foreign policy is actually three interconnected fights, it could well be that, despite their other disagreements, he and Paul find common cause against more aggressive neoconservative voices.

Kevin A. Lees is an attorney in Washington, D.C. and editor of the foreign policy blog Suffragio.org.

Image: Wikimedia Commons/Brendan Mruk. CC BY-SA 3.0.