AM I IMPERIAL OR NOT?: Comments on a Bill Quick post inspire Bruce R. to post up something on why America is not an empire, not yet, because of our experiences with the Philippines:

So, five years after America is finally free to engage in imperial adventure, they do. They get the Philippines out of it. But the ensuing four years of pitched battle with the Filipinos proves deeply dehumanizing. It's a course entered into already amid much doubt... Kipling's "White Man's Burden" was aimed at Americans hesitant to join the European mugging of the colonies. And some ignorance... President McKinley justifies it by saying it'll bring "Christianity" to the Catholic Filipinos. But by 1901, it's clear that Americans just aren't inclined to be casual about the stories of cruelty coming back home... so they start the switch to something rather novel for the times, a policy of restoring as much autonomy as possible to the lesser countries they happen to capture, albeit within an American economic sphere of influence... it's a policy they've followed more or less up to today.

I believe the Philippines experience also had a profound impact on the opinion leaders of the time, particularly presidents Roosevelt (who took office after the worst atrocities had ended), Taft (himself once administrator of the Philippines) and Wilson. In the early 1890s, Roosevelt is talking about America seizing hold of its destiny and spreading its reach; in 1905 he's pledging to Latin America that the U.S. has no territorial designs in the Western Hemisphere, and saying the U.S. must act maturely and fairly to the Filipinos. It's not stretching it too far to say that Quick, when he argues that America is not an imperial nation, is channelling the Rooseveltian consensus, post-1901. But, like Kurtz's killer in Apocalypse Now, the U.S. had to go into the heart of darkness, complete with water torture and reconcentrados, in order to firmly reject it. One could argue the Iraq situation is going to test the firmness of that rejection before long, so I do believe it's worth revisiting exactly what America turned its back on.

There's also a link to this overview of the "Pacification of the Philippines." But go read Bruce's post, there's quotes by American soldiers who committed atrocities, stuff that isn't too well-known today. I think Bruce is arguing that the Philippine experience was traumatic enough to get America to swear off imperial ambitions, so maybe that (the traumatic part) is why it's such a barely-discussed period in American history.