April 14, 2010 ABC Nightline

"One of my first sergeants asked me loudly, 'You're not a part of any terrorist organization or anything, are you?'" recalled Klawonn. "I was like, 'Whoa, are you kidding me?'"

He said he has been called all kinds of names by his fellow soldiers -- raghead, sand monkey, Zachari bin Laden.

"They're all terrible names, but the one that really hits me hard is to be called a terrorist," Klawonn said. "My heart drops every time I hear that."

Klawonn said he reported the incidents and others to his superiors, and he was shuffled around to other bases. From Nightline