

Sen. Rand Paul, R-Ky. speaks on Capitol Hill in Washington. (AP Photo/J. Scott Applewhite, File)

In the last 48 hours, two likely Republican presidential candidates have exchanged foreign policy body blows via op-ed.

First came Texas Gov. Rick Perry, who blasted Kentucky Sen. Rand Paul in a piece over the weekend in the Post. Perry writes that Paul believes "our nation should ignore what’s happening in Iraq", adding that Paul is "curiously blind" to the threat to American interests posed by ISIS. Paul, not one to avoid verbal fisticuffs, answered back in Politico Monday morning. "Governor Perry writes a fictionalized account of my foreign policy so mischaracterizing my views that I wonder if he’s even really read any of my policy papers," writes Paul. (Our favorite part of Paul's op-ed? His attack on Perry's hipster glasses; "Apparently his new glasses haven’t altered his perception of the world, or allowed him to see it any more clearly." writes Paul of Perry.)

Putting aside the verbal slap fight, there is something very important going on here. The most important paragraphs in either op-ed -- as it relates to the future (and the past) of the Republican party -- are these two written by Paul:

On foreign policy, Perry couldn’t be more stuck in the past, doubling down on formulas that haven’t worked, parroting rhetoric that doesn’t make sense and reinforcing petulant attitudes that have cost our nation a great deal.

If repeating the same mistakes over and over again is what Perry advocates in U.S. foreign policy, or any other policy, he really should run for president. In Washington, he’d fit right in, because leading Republicans and Democrats not only supported the Iraq war in the first place, but leaders of both parties campaigned on it in 2008.

What Paul is proposing is that he is the Republican candidate willing (and able) to handle the party's long-delayed reckoning with the war in Iraq. That conflict, premised on the false idea that Saddam Hussein possessed weapons of mass destruction, has never been fully litigated within the GOP. President George W. Bush spent his time in office defending this rightness of the effort, and the party's 2008 presidential nominee, Arizona Sen. John McCain, was arguably even more hawkish than Bush on Iraq. In the aftermath of the 2008 loss, the voice that filled the leadership vacuum for Republicans was former Vice President Dick Cheney, who steadfastly defended the policies of the Bush Administration. Four years later, the struggles of the domestic economy pushed discussion of Iraq (or any other foreign policy issues) out of the public's collective consciousness.

Even while Republicans were avoiding the debate over whether the party had made a major mistake in its policies toward Iraq, the political consequences were being made plain. Democrats retook control of the House and Senate in 2006 due, at least in part, to Bush's fading numbers on Iraq. Then-Illinois Sen. Barack Obama's entire candidacy -- for the Senate and later the presidency -- was premised on his opposition to the war in Iraq. Without Iraq, it's difficult to see how Obama finds a foothold against Hillary Rodham Clinton in 2008. Without Iraq, the race between Obama and McCain in 2008 is far closer.

The back-and-forth op-eds between Paul and Perry make clear that the debate about Iraq, the mistakes made there and what it means for Republican foreign policy going forward will be a prominent feature of the 2016 Republican primary race. And, there is reason to believe that Paul's position on Iraq is one shared by a relatively large number of Republicans. In a June New York Times/CBS News poll, 63 percent of self-identified Republicans said that the war in Iraq was not worth it.

The problem -- or, at least, challenge -- for Paul is differentiating between his foreign policy views and those widely attributed to isolationists. Here's his attempt to walk that line:

Strength does not always mean war. Reagan ended the Cold War without going to war with Russia. He achieved a relative peace with the Soviet Union—the greatest existential threat to the United States in our history—through strong diplomacy and moral leadership.

What Paul is arguing is that the war in Iraq was a mistake because his party (and many Democrats) didn't take the time to think through all of the consequences of it beforehand. And that being the most powerful nation in the world doesn't mean that always taking the most muscular option when it comes to dealing with other countries is the right thing to do.

Politically speaking, that position leaves Paul open to the attack that he a) doesn't think America is what it was once and b) is less-than-hard-edged on the war on terrorism. Again, Perry: "Paul’s brand of isolationism (or whatever term he prefers) would compound the threat of terrorism even further."

This is the opening skirmish in a much broader fight about the future of Republican foreign policy that is coming in the 2016 campaign. Paul is the catalyst of that important conversation. But can he also win the debate -- policy-wise and politically?