Of course, it could be simpler still.
After all, you blew up their buildings and killed tens of thousands of their civilians. and continue to do so.
Nor was that the first instance, 'You' have been funding 'their' wholesale slaughter for decades. Why? Who knows. Maybe Oil. Maybe they say different prayers at night. Maybe you just don't like brown people.1
Whatever the perjorative rationalisations the fact remains that your goal is to maintain and expand your way of life. You will kill those (or even better pay others to kill those) who genuinely think and act differently and choose to fight back when their way of life is threatened.
When we talk about violence, often we are really talking about the breakdown in social order, which is in large the compromise of compatible values that allows us to function together as a community. When we decide that we've been wronged, we reject the values that have been expressed, even when often the act masks the very same values that we ourselves would express in that situation.
Perhaps we've overdeveloped the "enemy's" sense of vengeance?
1No, I'm not accusing the rather excellent previous author of racism. I'm making a point about greed, religious intolerance, and xenophobia. We accuse the terrorists of two of these and I wanted to demonstrate how insidious these tendencies are when we employ them in our thinking and how hard to extricate.