In a front page story published on Thursday, the influential US daily said it ignored stories and information that questioned whether President George Bush really had evidence that Iraq was pursuing an illicit weapons of mass destruction programme.
"We did our job but we didn’t go enough, and I blame myself mightily for not pushing harder," assistant managing editor Bob Woodward says in the story.
"We should have warned readers we had information that the basis for this was shakier than many believed," Woodward adds.
Pentagon correspondent Thomas Ricks is quoted as saying that "there was an attitude among editors: Look, we are going to war, why do we even worry about all this contrary stuff?"
Stories that questioned the justifications behind the war and cast a doubt whether the US was doing the right thing by invading Iraq were relegated to the inside pages
Veteran reporter Walter Pincus put together a story questioning whether the Bush administration had proof that Saddam Hussein was hiding weapons of mass destruction.
But he ran into resistance from the papers' editors. His story was relegated to Page A17.