Jeff Zeleny of The New York Times sees a GOP edging away from the foreign policy positions of the Bush era:
The hawkish consensus on national security that has dominated Republican foreign policy for the last decade is giving way to a more nuanced view, with some presidential candidates expressing a desire to withdraw from Afghanistan as quickly as possible and suggesting that the United States has overreached in Libya.
The shift, while incremental so far, appears to mark a separation from a post-Sept. 11 posture in which Republicans were largely united in supporting an aggressive use of American power around the world. A new debate over the costs and benefits of deploying the military reflects the length of the conflicts in Afghanistan and Iraq, the difficulty of building functional governments and the financial burden at home in a time of extreme fiscal pressure....
The evolution of thinking inside the party is coming into view as Republicans begin sorting through their field of candidates to select a nominee to challenge President Obama, who faces a decision this summer about a troop withdrawal in Afghanistan. It could leave some of the party’s presidential candidates at odds with its most influential voices on foreign policy, like Senator John McCain of Arizona, who continues to call for an aggressive military effort to stabilize Afghanistan.
Read the whole thing here. In addition to the factors listed above, Zeleny attributes the shift to "the rise of the Tea Party movement," "a growing sense that the United States can no longer afford to intervene in clashes everywhere," and the ways the "killing of Osama bin Laden has intensified questions about the need for prolonged American involvement in fighting Al Qaeda." He doesn't mention another, more cynical explanation, which is that it's always easier to oppose intervention abroad when the other party's in power. That's true whether you're Barack Obama criticizing George Bush's war in Iraq or Michelle Bachmann criticizing Barack Obama's war in Libya. (For the record: I'd rather see politicians taking the right position temporarily for reasons of expediency than taking the wrong position for any reason at all. If reform relied on pols becoming principled, we might as well move to Somalia and start over.)
Also worth a read: John Feehery claims we're witnessing the collapse of what he calls (a little anachronistically) "the Cold War consensus." When it comes to military intervention, he argues, "Republicans are now listening more to Ron Paul than they are to Dick Cheney."
Update: Adam Serwer says more about that in-power/out-of-power dynamic:
There's an element of highly convenient partisanship...where gestures toward foreign policy realism offer an opportunity to criticize their predecessors' military interventions. But then they get in office and change their minds. And maybe that's because regardless of what the candidates say, the foreign policy establishment in the GOP is still mostly neoconservative, while in the Democratic Party it's still mostly made up of liberal internationalists, and these are the people presidents from either party end up taking advice from.