Thousands and thousands of people, whose only crime was living in the wrong place, are dead because of our lust for oil. Together with our open-ended support of the ethnic cleansing of Palestinians and the backing of the most oppressive regimes, it shouldn't be any mystery about what motivates "terrorists."
Yet we live in a democracy and can change policies. The innocents we kill don't have that opportunity. Our choices -- or rather, our willful ignorance -- have consequences.