Oliver Wendell Holmes sums it up

"When a nation is at war many things that might be said in time of peace are such a hindrance to its effort that their utterance will not be endured so long as men fight and that no Court could regard them as protected by any constitutional right."

Oliver Wendell Holmes in Schenck v. United States.

Compare and contrast today's MSM and the likes of Kerry and Murtha. The T word comes to mind.