Let's clear out Germany first, because it's easier. Germany was a Western nation, and its people were well aware of Western liberal values. As a matter of fact, one suspects that Germans wouldn't have abandoned the noble values of the Weimar Republic were it not for the Great Depression. Bringing Germany (specifically, West Germany) back to democracy was not so much the introduction of a totally alien set of values and norms but rather a return to an earlier, and never totally abandoned, state of German liberalism. This is, therefore, less than a compelling example for people who thought that invading Iraq was a good idea.
Japan seems like a better example of grafting a new and alien form of government onto a country that has no history of it. But this example doesn't exactly cut the mustard either. Japan was a democracy in name only, due to extensive meddling from the United States in the form of money as well as support for Nobusuke Kishi, one of the most notable statesmen of postwar Japanese politics, who was bought and paid for by the CIA. This is sort of like saying Greece was some sort of great example of the Western liberal consensus during the Cold War, when in fact we fixed the Greek elections in 1956 to ensure that the Christian Democrats would win. Indeed, Japan's democracy is less than ideal today--it's essentially a one-party state, though it is admittedly stable. That's not nothing.
The truth is that there simply wasn't any good precedent for assuming that our little Iraq experiment would work, though these flimsy examples were certainly good enough for Bush, who used them constantly. It is unsurprising that neither he nor Goldberg really knew much about history, aside from perhaps having seen an hourlong History Channel documentary or two. The truth is that all this pablum about how democracy is the natural state of man is just wrong. Humanity went for millennia before discovering democracy, and while I like it and find it more appealing than the other forms of government I find it a sign of a remarkable hubris to suggest that it's somehow built into the genetic code of humanity, while evidently evil isn't, and is rather something that Bush, Cheney, and John McCain thought we could defeat. Then again, "George W. Bush doesn't understand much about the religion he is a part of" is pretty much a dog bites man story at this point.
No, evil can't be defeated, as it's in every human heart along with good. One doesn't have to dig deep to find the chinks in the neocon worldview, as one immediately sees signs of a lack of understanding of human nature and history, coupled with an intolerable smugness and hubris. Many conservatives take their country for granted when they make arguments that are variations on "My country, right or wrong". Indeed, Goldberg does a variation of just that, and Beinart's rebuttal is thoroughly satisfying. What the neocons did, basically, is to take democracy for granted. As I stated, I like democracy an awful lot and wouldn't have it any other way, but there are some very real problems associated with democracy, and in particular American democracy, as any blogger could no doubt tell you.
Kevin Drum has some good stuff as well:
In fact, Bush always struck me as less serious about democracy than his predecessors. To him it was a nice slogan — every American politician is in favor of democracy, after all — but anyone who's serious about democracy knows that it's not the kind of thing you can get overnight. It depends critically on education, on institutions, on culture, on overcoming corruption, on property rights, on the rule of law, and a dozen other things. None of these were things that Bush ever seemed to have the patience to bother dealing with.
This gets at the practical difficulties of democracy promotion. The focus on elections was mostly a function of Bush's particular methodology--the much-vaunted MBA president who, like all MBAs, needs to have everything quantified. Having elections in countries provides quantifiable results, but as Bush learned those results can make things even worse for the United States. A lot of the stuff Kevin mentions is important, but difficult to quantify. This doesn't even get at the question of whether we have either the right, the responsibility, or the wisdom to do this kind of thing. I am dubious that we have any of them. I think it's become clear, throughout decades of meddling in the Middle East and Latin America, that this sort of influence, regardless of how it's intended, tends to do little more than breed anti-American hatred and suspicion. And the notion that America--home of the routine bunker-busting budget deficit--somehow has the credibility to tell others how to govern themselves would be laughable if so many people didn't actually believe it.
In his book, Heads In The Sand, Matt Yglesias made a point that the neocons have yet to answer: if one assumes that the arc of politics bends toward democracy, if that is the final stage in human development (as ex-neocon Francis Fukuyama wrote), then why do we need to wage expensive wars to bring democracy about in foreign lands? Shouldn't we take a cautious and restrained approach, aiding democratic movements from behind the scenes? It's amazing how quickly the tapestry falls apart, and all one sees afterward are arrogance, restlessness and unjustified expansionism, and ignorance. How these people ever held power is a mystery to me, though the only way they could was by waiting for a suitable crisis to ram through a bunch of wooly abstractions that only made sense because Karl Rove's organization scared the living hell out of everybody.