If you are a proud American, you're sinning. Not only that but also what a bad time to fall to the sin of being proud (puffed up and haughty) considering all the extremely shameful, evil things that the government of the U.S. and especially the Bush administration has been doing. The list is too long to list. Who doesn't know all the evils that have been spread across the news even as the mainstream tried desperately to spin Bush in a good light? It can't be done. One might have been able to plea ignorance back in 2001 about Bush before 9/11, but once he started in on the Axis of Evil nonsense, the excuse of ignorance started fading fast. Once he ignored the U.N. and was caught bribing and spying on U.N. delegates and wanting to cut short the weapons inspections, all excuses were gone.
Pride goes before the fall. That's Biblical.
Anyone who follows the dictum of "My country right or wrong" is wrong. My country right only. That's the way it's supposed to be. When your country is wrong, you owe it to God to resist.
Also, violence is a sin. Militarism is a sin.
Read the other posts and pages on this site. I'm not going to reproduce it all here.
Just don't add to your sin by calling yourself a Christian if you're ever proud to be an American.