It's true that some Republicans are sounding anti-interventionist notes now. George W. Bush himself ran in 2000 as an anti-interventionist, attacking the Clinton administration for its nation-building and promising a more "humble" foreign policy. The Republican fear of reckless American intervention disappeared as soon as Clinton did, and it will disappear again as soon as a Republican takes the oath of office.Obama may have "sounded far more anti-war" in 2008 than he turned out to be in office, but I think it's a closer call than Chait here implies. He ran to the hawkish side of John McCain on Afghanistan, Pakistan, and on bin Laden (and, by implication, directly attacking other terrorist leaders); he's governed basically that way. On Iraq, he's basically more or less done as he promised. One could certainly argue that the Libya operation is consistent with Obama's campaign calls for multilateral, rather than unilateral, action.
This is, to be sure, a bipartisan phenomenon. Barack Obama and many other Democrats sounded far more anti-war while running for office than Obama has governed. The point is that campaign rhetoric about foreign policy, while interesting in its own right, does not provide an accurate guide to how a party would contact foreign policy from the White House.
What I think one can say about foreign policy and elections is that the issues are perhaps a lot less predictable than in domestic policy. It's hard to assess how to translate Obama's campaign rhetoric into how he should act in Libya because the context is so radically different than anything he was asked about in 2008.
In general, however, the thing to pay attention to, the thing that is probably most predictable from the campaign, is the set of foreign policy advisers that a candidate is likely to listen to once in office. If in fact it's the case that Republican elites are still as interventionist as ever, then that suggests that, indeed, any winning GOP nominee will wind up following policies similar to those of George W. Bush. Of course, one can also point to differences within Bush's administration, and I do think that the president's personal feelings and temperament probably matter in some cases, but still: personnel are a good indication of policy.
I think that would have worked pretty well for Obama, by the way. It's true that some wishful thinkers on the left seem to have envisioned him as a less flaky Dennis Kucinich, but my memory is that Obama's foreign policy staff during the campaign was well within the Democratic mainstream -- strongly internationalist, if quite a bit less hawkish than Bush's team.