To fully appreciate how the post-election Republican party is warring with itself, check out the internecine battle over Chuck Hagel's Secretary of Defense nomination. If Obama, by choosing a Republican and decorated Vietnam war vet, was aiming to divide the GOP and expose its internal split on foreign policy, then he's already succeeding.

The intra-Republican rift was on full display this weekend, as the militarist neconservatives (who fomented the disastrous Iraq war) took heat from the party's aptly-named "realists" (who rightly cite Iraq as proof that America should go to war only as a last resort). Ex-Nebraska senator Hagel, who, unlike the armchair-warrior neocons, actually knows what war is like on the ground, got plenty of support in the press and on the Sunday shows from the saner wing of the GOP foreign policy establishment.

It remains to be seen whether the realists can ultimately persuade Republican senators to confirm Hagel, but that's a story for another day. For now, the GOP's identity crisis is sufficient grist. As conservative think tank scholar Danielle Pletka points out, the party that once owned the foreign policy brand is burdened by "dissension within its own ranks." She says that "the ideological divisions buried during the (2012) campaign have already resurfaced and must be dealt with," because at this point, on foreign policy, the GOP has "lost the confidence of the American people."

Hagel's nomination merely exacerbates these internal Republican tensions. For weeks, the neocon camp led by Iraq war cheerleader Bill Kristol dominated the dialogue, painting Hagel as a wuss who would refuse to go to war. (The neocons have reached the point, in their ongoing devolution, of opposing a Purple Heart winner who enlisted to fight in Vietnam.) But this weekend, we finally heard from realists of long Republican service: Richard Haass, Richard Armitage, and Colin Powell.

Haass, who runs the nonpartisan Council on Foreign Relations, told ABC News: "There are many virtues in having a secretary of defense who questions confident predictions of what would stem from recommended uses of military force." In translation, Hagel by dint of his practical experience (he'd be the first enlisted soldier to run the Pentagon), would provide a check and balance in times of war fever. Haass essentially argued that a perspective such as Hagel's would be an asset inside the loop.

Haass is particularly incensed by the neocon claim that Hagel is "anti-Semitic." (Neocon Elliott Abrams, another Iraq war cheerleader, recently slapped that label on Hagel during an NPR interview.) Haass said yesterday that Abrams was wrong to launch an "ad hominem attack" just because Hagel occasionally questions Israeli policies. Haass saw it as further evidence of our debased political culture: "We often ask, why are public debates bitter? Why aren't sometimes the best people going into public life? This is one of the reasons."

Abrams is actually a Council on Foreign Relations fellow - yet here was Haass, on a Sunday show, tagging one of his own scholars as a smear artist. When I refer to Republican foreign policy mavens at war with themselves, this is what I mean.

Meanwhile, Richard Armitage, a national security adviser under three Repubican presidents, has been warring with the necons for nearly a week. With savage sarcasm, he's telling the press that Hagel "is the neocons' worst nightmare, because you've got a combat soldier...who actually thinks there may be other ways to resolve some questions other than force." Hagel would "disenfranchise their notion that there’s a military solution for every problem."

And on Meet the Press, Colin Powell offered a corrective to the neocons: "(Hagel) knows what war is and he will fight a war if it’s necessary, but he’s a guy who will do it with great deliberation and care....For the last three weeks, we have had dueling op-eds and dueling blogs and dueling different groups coming forward, but most of the national security community in retirement that I know and many of the secretaries of defense and state that I know, and national security advisers, and very distinguished ambassadors who served in the Middle East, think that Chuck Hagel is a solid guy."

Powell also said of the neocons: "They're fully entitled to their views, and I didn’t ever think they would go away and not be heard from again. But they have to remember one thing. It's President Obama, not President McCain and not President Romney, they've lost two elections. The American people have made it clear that they are not particularly interested in finding new conflicts to get into. And are not particularly interested in saying, you know, 'sanctions are just a road bump on the way to bombing.' We should be very, very careful when we sort of toss around theories of use of military for situations that might be resolved in other ways."

And there it was, the bottom line: The Republicans have lost two presidential elections, in part because most Americans have lost faith in neocon military adventurism. The GOP's realist wing understands this, and recognizes that - short of scandal - a victorious president should have the right to assemble his own foreign policy team. But the neocons are congentially unable to grasp that fact, and so the foreign policy struggle within the GOP will continue. The risk, accpording to conservative scholar Danielle Pletka, is that it will perpetuate its "failure to define of a vision."

And that failure was already obvious in the November exit polls. Among the small subset of voters who cited foreign policy as America's most important issue, 56 percent said they had more confidence in Obama to run the show - and only 33 percent chose Mitt Romney. If the GOP wants to further damage the brand it once owned, it need only keep warring with itself over Hagel.

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