Here are some of the bits I liked best from Susan Moeller's appearance on Booknotes, discussing her cleverly titled book, "Shooting War: Photography and the American Experience of Combat." [emphasis mine]

[Talking about a photo printed in Life Magazine in September 1943]

"MOELLER: The reason it's pivotal is that it was one of the first three photographs that were released of the American dead. So it's the first time in 50 years that Americans saw Americans who had been killed in combat. Up to that 1943 date, censorship for World War II was the same as for World War I. You couldn't show graphic pictures of any kind."

...

"World War II was the war that everyone felt needed to be fought. It was a good war. But the Korean War people had much more ambivalent feelings about -- so the photographs that came back mirrored the ambivalence."

...

[Discussing the controversial photograph of a South Vietnamese general using a revolver to shoot an alleged Viet Cong lieutenant in the head, in the street.]

"MOELLER: Well, it was very controversial for all kinds of reasons. It raised questions about how far photography go. How much should the media show us. But more importantly than the journalistic issues, it raised questions about was this a war that condoned that kind of action. Was that a war that Americans wanted to participate in?

LAMB: I can even remember -- and this is 20 years later -- that it was General Loan.

MOELLER: It was General Loan.

LAMB: I mean, did it have that kind of an impact on all us?

MOELLER: Yes. It really did."

There's video footage of that execution, which I have unfortunately seen, not just still photos. It's probably on YouTube, if you're inclined to search for it.