April 14, 2010 -- Army Spc. Zachari Klawonn is exactly the kind of soldier the military says it needs. He's the son of Kansas-born father and a Moroccan mother, raised as a Muslim and able to speak Arabic. He's been recognized for his exemplary performance in the Army, and his commanders even identified him as a candidate for Special Forces selection, a road to joining the elite Army unit.

"I really do think he's the best soldier in our battalion, hands down," said Spc. Arnold Mendez, a friend of Klawonn's.

"Anytime somebody tells him what he can do, he does it," said another friend, Spc. Daniel Arndt.

Klawonn, 20, has earned the praise of his fellow soldiers and his commanders, but he said there are others in the military who have offered nothing but abuse. Since he enlisted, Klawonn has perceived a pattern of harassment for his religious beliefs -- name calling, threats and worse from both his peers and from officers. The abuse has felt so severe, Klawonn has questioned whether he can endure.

Watch 'World News' and 'Nightline' tonight for more on Spc. Zachari Klawonn.

Born in Morocco, Klawonn grew up in Bradenton, Fla. He was a standout on his high school golf team, with thoughts of trying to go pro, but his plans changed after his dad's unexpected death from cancer. At age 15, Klawonn had lost the man he thought of as his best friend and was searching for a larger purpose in his life.

His dad was an Air Force veteran who had told his son fond stories of his time in the service. Klawonn began to consider joining the military.

"I was excited to, I guess, defend America," he said. "Do that, we call it, hoo-ah-hoo-ah stuff. ... It seemed very honorable and admirable. It was something I could be happy about and say, 'OK, I've done something very good.'"

Against the wishes of his mother, Klawonn enlisted in the U.S. Army in July 2008.

As soon as he started basic training, Klawonn said, the discrimination began.

With Klawonn standing alongside 400 new recruits, he said, a drill sergeant read out loud a list of religious services, and when he got to the Islamic service sarcastically asked if anyone planned to attend.

"I raised my hand, and he was shocked," recalled Klawonn. "Then, he called me out of formation, took me to the front and basically made a mockery of it."

In the final, most important exercise of basic training, Klawonn's trainers picked him out of all the soldiers to play the role of a terrorist. He was shocked, as were his friends.

"They wrapped some cloth around his head," remembered Pfc. Chad Jachimowicz. "We'd have to put him down and have guns drawn on him. ... I had to shoot my own battle buddy, and I had a real problem with that."

Another time, Jachimowicz said he was with Klawonn when they walked into the laundry room in their barracks on base. According to their account, they found pages ripped out of a book and scattered on the ground. Picking up one of the pages, Klawonn saw the text and realized it was his Koran. Someone apparently had stolen the book from his room and desecrated it.

"It's aggravating to see how they treat him on a daily basis," said Jachimowicz.

"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.

When asked about Klawonn's case today, the Army provided a statement to ABC News: "Senior Army leaders were unable to comment on the story because of the ongoing investigation. ... Army officials who viewed the [ABC News] piece applauded his candor, and that of his fellow soldiers, in telling his story."

Klawonn said he was transferred to Korea for a time, and then returned to Fort Hood with his unit in December 2008.

In his third week at Fort Hood, Klawonn said, he was walking out to his truck when he saw a piece of paper tucked underneath the wiper on his windshield.

"I took the letter out, read it, and it said, 'Hey carpet jockey, go back where you came from,'" Klawonn said.

The alleged discrimination at Fort Hood didn't end there, according to Klawonn. The name-calling continued, Klawonn said, adding that he even had a bottle thrown at him from a passing car when he was wearing his religious robes.

Nearly a year after Klawonn arrived at Fort Hood, on Nov. 5, 2009, Maj. Nidal Hasan, a Muslim, opened fire at an Army processing facility on base. He killed 13 people and wounded dozens more.

Klawonn had never even heard Hasan's name, but he knew that Hasan's crime would result in more problems for him.

"I knew people were going to immediately and automatically draw a comparison between us, just due to the fact that we were both Muslim," he said. "There was a vibe that people weren't coming around to talk with me, and they really asked me to justify the situation, you know, why he did that."

"I felt like there was a lack of trust within the group around me," Klawonn said. "I heard rumors. You know, 'Watch Klawonn, see what his friend did? See what his brother did?'"

Then in February, someone did more than just call him a name, he said. At 2 a.m. on a Monday, Klawonn said, he was startled from his sleep by a loud beating sound on his door. Someone was kicking the door so hard, he could almost feel it in his bed. At first, he thought it was some kind of fire drill, but then he cracked open the door.

"A note falls that was wedged in the door," he said.

It read, ''F--k you raghead, burn in hell."

Klawonn said he went running through the hallway, trying to catch the person who did it, with no success. He reported the incident to his commanders, and he said their solution was to have him move off base for his safety.

He does feel safer, but he's frustrated by the way he said the Army has handled the harassment.

"I've filed complaint after complaint," he said. "There's really no closure or justice with any of the cases. I state my problem, they say there'll be an investigation that's ongoing, and then it's kind of swept under the rug."

After the February incident, Klawonn was given 10 days of leave and went home to Florida. There, for the first time, he shared his experiences with his family.

When he returned base, he was ready to do something about the alleged discrimination, a problem he believes is widespread for Muslims in the military. The Washington Post published an article about his story, and other soldiers, perfect strangers, wrote to offer support.

One high-ranking officer wrote, "I want to let you know I would be honored to share a foxhole with you any day."

Another message came from Dorothy Carskadon, a captain in the U.S. Army Reserves, who herself was wounded during the Fort Hood shooting.

"Dear Specialist," Carskadon's letter said. "I am always sorry to hear about harassment and bigotry in the military. ... I would be proud to serve with you. I am sorry for the harassment that you have experienced due to me getting shot. It is unfair and unwarranted."

Klawonn hopes to use his message to help other Muslims in the military. He wants to see Islamic prayer services held on base on Fridays, and he thinks the Army could do more to prevent the kind of discrimination he said he's experienced.

"I'm not asking for a handout," he said. "I'm not asking for any special treatment. I'm asking for the bare essentials and the due rights that the rest of the soldiers have."

After all the hatred he said he's experienced, Klawonn has never regretted enlisting because he joined the Army with a higher purpose -- protecting the American dream.

"The constitutional rights that we have and the freedoms we take for granted are near and dear to my heart," he said.