The photo below captures everything that Americans wanted to believe about the Iraq war in the earliest days of the invasion in 2003. Pfc. Joseph Dwyer, an Army medic whose unit was fighting its way up the Euphrates to Baghdad, cradles a wounded boy. The child is half-naked and helpless, but trusting. Private Dwyer’s face is strained but calm.

If there are better images of the strength and selflessness of the American soldier, I can’t think of any. It is easy to understand why newspapers and magazines around the country ran the photo big, making Private Dwyer an instant hero, back when the war was a triumphal tale of Iraqi liberation.

That story turned bitter years ago, of course. And the mountain of sorrows keeps growing: Mr. Dwyer died last month in North Carolina. He was 31 and very sick. For years he had been in and out of treatment for post-traumatic stress disorder and addiction. He was seized by fearful delusions and fits of violence and rage. His wife left him to save herself and their young daughter. When the police were called to Mr. Dwyer’s apartment on June 28, he was alone. They broke down the door and found him dying among pill bottles and cans of cleaning solvent that friends said he sniffed to deaden his pain.

He had been heading for a disastrous end ever since he came home.

Two of his best friends were Angela Minor and Dionne Knapp, fellow medics at Fort Bliss, near El Paso, Tex. For a while, they were part of a small, inseparable group that worked together, ate out, went to movies and called one another by their first names, which is not the military habit.