Among the 17,000 injured in Iraq, nearly half have not returned to duty.
But there are a remarkable few who, despite losing limbs, have fought to return to the fight.
Capt. David Rozelle is one of the trailblazers. As a tank commander in Iraq in 2003, he survived a mine explosion that blew off the front end of his Humvee.
"Gave my last command as a cavalry troop commander, which is secure the area and evacuate casualties," Rozelle recalled. "I was the casualty. They got me out."
Rozelle's right foot was amputated, which could have allowed him to retire. Instead, he battled drug and alcohol dependency and worked to get back in the fight against insurgents.
"They made a decision on that day that I was going to get injured," he said. "But I wanted to turn it around and say, 'I can beat this.'"
Eighteen months later, Rozelle became the first officer to lose a limb and return to command in Iraq.
"I went back and I faced the demon," he said. "I overcame my fears, and I went back to war."
Now he has a new mission. As administrator of the amputee unit at Walter Reed Medical Center, Rozelle is helping others who want to follow in his footsteps.
Sgt. Tim Gustafson, a National Guardsman, lost his right leg in a roadside bomb attack and is working to return to frontline duty. "I definitely think I can be duty-ready," Gustafson said.
Only 10 soldiers who have lost a limb have returned to the battlefield. But 26 have returned to active duty.
Marine Sgt. Sean Wright, injured in the battle for Fallujah, was one of them. "First, I saw my left hand and thought, 'Well, great, that's gone,'" he said. "And I looked over at my right hand and that was gone and I thought, 'Well, there's both of them.'"
But he was so determined to remain a part of the Marines that he found a new job. The sergeant who lost both his hands is now teaching martial arts to his fellow Marines. And he said he would go to Iraq again if he could.
"I think about that all the time," Wright said. "I get so jealous. You know, I'd love to be over there running those patrols and those missions with those guys."
But now, these injured men say their new mission is to lead by example and show other amputees what is possible.
ABC News' David Kerley reported this story for "World News Tonight."