Dan Drezner and Scott Lemieux both discuss IR hotshots John Mearsheimer and Stephen Walt's article in the London Review of Books about the Israel Lobby , and how it has diverted America from the foreign policy path Realists would expect.
Or to put it more bluntly, the Jews got Bush to do stuff that helps Israel, but hurts America.
As Drezner notes, this is the kind of subject that makes students tense. But, of course, it is pretty much received wisdom in most of the world, so it hardly makes sense for Americans to duck the issue on political correctness grounds.
If we look at the "Israel Lobby" as an example of a broader species of international ethnic solidarity and its influence on the foreign policy of multiethnic states, we at least achieve a more comfortable level of abstraction. Strict IR Realism, by employing the reification of "state interests," rules out the possibility that the ethnic mix of a country might influence its foreign relations.
According to Edwin O'Connor's mayor in The Last Hurrah, there were only two things an aspiring municipal politician in mid-century Boston needed to know: first, that Trieste belongs to Italy, and second, that all Ireland must be free.
Clearly, Canada, viewed as a unit, got itself into lots of conflicts that make no sense from a Realist perspective because of the ethnic loyalties of its British population. The canadiens understandably objected to this. Since the natural federal allies of canadien nationalists tended to be reactionary old stock Brits, this repeatedly led to the breakdown of the federal blue coalition. This might happen again over Afghanistan.
Of course, to Anglos at the time of the Boer war, it made no sense to talk about Canada's international interests as distinct from the Empire's as a whole. Arguably, it still doesn't make sense to pro-American Canadians today. Even anti-American Canadians tend to define their international views as if they were part of a domestic opposition in the US. Canadians are most comfortable talking about "our" interests in trade disputes, where it is, however, least appropriate: American home buyers ought to like $0.25 per metre stumpage rates, and BC taxpayers ought to dislike them.
Realism has an undeserved reputation for mental toughness, but it depends on a pretty sentimental vision of a common national interest. It's good to see that Mearshmier and Walt are beginning to think about this, although maybe they should have taken a wider perspective.
Added: thanks to Scott Lemieux for the link. Blogging is a lot harder than being a pest in somebody else's comment box.