Of course. And I'm not saying those reasons justify the actions. But I am saying that the United States is guilty of its fair share of destructive, murderous action in the Middle East. Its not like some radical Muslims just woke up one day in a vacuum and said "you know what? We'd really like to murder 3,000 Americans today because it would be fun." And though I don't know all the history about every event, I don't doubt Americans thought they could do some good when they intervened in the Middle East (though they were wrong.) Recognizing that the motives of the Islamic fundamentalists are somewhat complicated definitively rules out the kind of wholesale slaughter that we're talking about here. Even if the Muslims were completely and totally without reasons for doing what they did, however, its still immoral to kill civilians. Always.
I don't really think a Christian can disagree with me on that point. Either you believe life was made in God's image and thus is sacred and should not be deliberately taken without just cause, or you are a godless utilitarian who believes that its OK to destroy, murder, that which was made in God's image "for the greater good" even if the person in question did nothing to deserve death. This view is anti-Christian and I'm not really of the mindset that there are any saved people that hold to it.