Interviews with enlisted men and former Marines at the base found many simply don't believe it was a massacre of 24 civilians in Haditha in November, and others saying if it happened, it was on commanders' orders, the newspaper said.
The killing took place after a Marine corporal was killed by a roadside bomb, and the Pentagon is investigating claims the other Marines snapped and went on a killing spree.
Jerry Alexander, a Navy man who served with the Marines for 12 years, said hindsight is dangerous.
"If I saw my buddy laying there dead, there is no such thing as too much retaliation," he said. "I would not prosecute these young men because they were just doing their jobs."
Cpl. Michael Miller, 25, who has served two tours of duty in Iraq, said he doesn't believe the Marines acted on their own.
"In Iraq, everything you do has to be cleared with a commanding officer," Miller said. "You just can't go clearing houses without the permission of higher-ups."