The recent Time/CNN report that the United States used nerve gas in Laos against defectors during the Vietnam War is a shocking indictment of the U.S. government. Given the particular emotions here attached to that war, Defense Secretary William Cohen was correct to demand a full investigation of the charge. He should go further, however, and release what the Pentagon knows about the situation to date.

Details about the charge were sketchy in the news report and are getting sketchier as the days go by. The primary source for Time was retired Adm. Thomas Moorer, who said that the 1970 Operation Tailwind in Laos used the nerve gas sarin against U.S. defectors. Earlier this week he said he had no independent knowledge that sarin was used, but had heard about it from servicemen. He also said that he was not certain of Operation Tailwind’s mission.

His uncertainty was echoed this week by retired military officers, who say they have never heard of the use of nerve gas against defectors. Maybe the Time-CNN report overstated the case or missed the mark altogether. Secretary Cohen accurately understood that finding immediate and thorough answers to these questions was essential to avoiding another generation of rumors and conspiracy theories about a war in which the U.S. government did so much to build distrust among Americans.

But it is also impossible to believe that one admiral knew of the horrible and dangerous mission he describes but no one else did. Or that the Pentagon would be unable to quickly identify the policy that allowed the use of the nerve gas. The alleged events in Laos weren’t so long ago that the Pentagon should have trouble explaining the situation fully and soon.