I think the distinction is not enthusiasm for war but with whom. The paleo-cons have always had a deep and abiding distrust for the state of Israel. They view any war in the Middle East through that lens. They see such conflicts in terms of Israel and the "Jewish lobby" as being not in our interests but in the interests of Israel. The Neo-Con "clique" is the mirror image of the Paleo-cons. It is not surprising that, over-time, the far-left and the far-right have finally reached the same point in their views of Israel and that conservatives have been fairly consistent in their views of our relationship with Israel and our strategic national interests in the region. The extremes of both the left and the right view the Middle East "problem" as Israel and the Palestinians. Conservatives view the Middle East as the entire region and its impact on the interests of the United States.
The paleos, by contrast, opposed our adventures in Somalia, Haiti and the Balkans as much as they oppose the current plans for war.
I don't think it's a so much a case of right and left ganging up on Israel, as simply wanting to back off somewhat and encourage more compromise, and not automatically identitifying our interest with that of Israel or Bosnian Muslims or other groups that they regard as dubious. Maybe compromise is impossible now, but it doesn't seem to me that they advocate treating Israel differently from other countries in the same position. For some people, it seems to boil down to whether Israel is "us" in the way that we thought Europe or Japan or Canada was us, or whether we ought to pursue a more distanced policy towards that country, but I don't think that those who are critical of our current Middle East policy are scapegoating Israel or that they aren't critical of other interventions elsewhere in the world.
There's a generalized support for a "forward policy" among neo-cons and a generally more restrained attitude among paleos. Perhaps paleos are less supportive of Israel than they would be of South Africa, and neos are more supportive of Israel than they would be of Taiwan or East Timor, but attitudes towards Israel alone isn't the governing factor.
I wouldn't attack the paleos for their inconsistency on Israel, but for the cursed consistency they show in attacking pretty much all the wars we've fought in, even the justified ones.