Why do American people Hate Iraqis?

I am 20 yo Iraqi male I ve been in America for 4 weeks when I talk to someone they do just well and speak to me nicely till they know I am Iraqi so they start saying bad things and just avoid me and never approach me again also in the last few years I managed to have American soldiers in Iraq as friends after lots of pain in the *** I mean when I try to talk to them they just make fun of me as Iraqi till they know me personally and only then they accept me as a friend I mean you couldn't judge people by their nationality or religion...could you? I mean is it skin or race issue but I have blue eyes and speak english the american accent