Jacob Heilbrunn wrote a piece recently wondering "where have all the serious Republicans gone [on foreign policy]?" Heilbrunn observes correctly that the loudest Republican voices on national security these days are advancing a variety of zany views, taking as evidence Mitt Romney's empirically-challenged attack on the new START treaty.
In a similar vein, Daniel Larison wonders whether a return to Republican "realism" is even anything to thirst for:
In practice, if the GOP “reclaimed its realist roots” I wonder how much would change for the better. Republican realism sounds good by comparison with what we have had for the last decade, but most actual Republican realists, especially those in elected office, did little or nothing to challenge the endless hyping of foreign threats and the frequent recourse to military intervention abroad in the ’90s... How many realists not affiliated with the Cato Institute expressed serious reservations about NATO expansion into Ukraine and Georgia before the August 2008 war? As sympathetic as I am to many realist arguments, and as much as I appreciate the efforts of the most sober realists to try to steer Republican foreign policy thinking in a constructive direction, until Republicans reject confrontational and aggressive foreign policy goals it will not matter very much if they adopt realist means and rhetoric.
The answer to Larison's question about NATO expansion is that it was quite unpopular among non-Cato realists. John Lewis Gaddis wrote at the time [.pdf] that "historians -- normally so contentious -- are in uncharacteristic agreement: with remarkably few exceptions, they see NATO enlargement as ill-conceived, ill-timed, and above all ill-suited to the realities of the post-Cold War world." He "could recall no other moment...at which there was less support, within the community of historians, for an announced policy position." That might have been putting things a bit too strongly when it came to realists, but not very much. That is, actual realists, who don't, by and large, get called to Washington.
This, I think, is the crucial distinction to make. The bottom line here is that there is a big disconnect between people in the Beltway who call themselves realists and actual realists. Ur-realist Kenneth Waltz once described himself as "a fierce critic of American military policy and spending and strategy, at least since the 1970s." John Mearsheimer points out that realists opposed the Vietnam War almost to a man (except for Henry Kissinger), and that realists opposed the Iraq War almost to a man (except for Henry Kissinger). Since at least the Johnson administration, realists have tended to be dovish relative to the Beltway consensus as it has existed at any point in time, and active dovishness is not permitted in polite company in Washington.
Not only is it a mistake to hearken back to a Glory Day of Republican Realism, it is really a mistake to characterize any existing Beltway faction as "realist." Belligerent nationalists, Wilsonians, liberal imperialists...all those we have. Realists, not so much.