Is there a shift in GOP foreign policy? No.
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 also highlights a renewed streak of isolationism among Republicans, which has been influenced by the rise of the Tea Party movement and a growing sense that the United States can no longer afford to intervene in clashes everywhere. - Jeff Zeleny
I very much doubt there's any kind of shift occurring. First, vague declarations on the campaign trail have no meaningful relation to how a candidate would govern if he or she were elected. Second, we've seen this movie before. In 2000, then-candidate Bush promised a "humble" foreign policy that would eschew nation building. We all know how that turned out.
The fact of the matter is that any significant "shift" in GOP foreign policy won't happen at the level of presidential hopefuls angling for the limelight. It will occur when the bureaucrats and policy-makers that would staff a future Republican administration turn meaningfully from the doctrines and orthodoxies that have shaped "Republican" foreign policy in the past. Is there evidence that such a shift is occurring? I don't see it ... do you?