Operation Tailwind was a covert incursion by a small unit of United States Army and allied Montagnard forces into southeastern Laos during the Vietnam War, conducted from 11 to 14 September 1970. Its purpose was to create a diversion for a Royal Lao Army offensive and to exert pressure on the occupation forces of the People's Army of Vietnam (PAVN). A company-sized element of US Army Special Forces and Montagnard commando (Hatchet Force) of the Military Assistance Command, Vietnam Studies and Observations Group (MACV-SOG or SOG) conducted the operation.

Nearly 30 years later, CNN/Time magazine jointly developed an investigative report that was both broadcast and published in June 1998 about Operation Tailwind. The TV segment was produced by April Oliver, Jack Smith, Pam Hill, and others. It was narrated by Peter Arnett, noted for war reporting, who had received a 1966 Pulitzer Prize for his work from Vietnam and who had worked with CNN for 18 years.

Entitled Valley of Death, the report claimed that US air support had used sarin nerve agent against opponents, and that other war crimes had been committed by US forces during Tailwind. In response the Pentagon conducted an investigation, as did CNN; the news organizations together ultimately retracted the report, and fired the producers responsible. April Oliver and Jack Smith sued CNN in a challenge of their dismissals and reached separate settlements with the network. After being reprimanded by CNN, Arnett resigned from the organization.

Several individuals who were sources for the reports, whose images were shown in the reports, or who were otherwise identified with the reports, brought other legal actions against CNN and Time Warner. A decision by the Ninth Circuit Court of Appeals in one of the cases states that the Tailwind reports did not defame the plaintiff who was a source for the reports. It noted that the plaintiff, in his interviews with CNN, "admitted the truth of each of the three facts he now challenges."