During the Vietnam War, the U.S. Joint Chiefs of Staff considered and rejected some additions to strategic bombing campaigns that would include targeting a series of dikes and dams along Vietnam's Red River delta. A classified 1965 USAF report suggested that the Red River flood control system could probably not be destroyed by conventional aerial bombing. President Richard Nixon and Secretary of State Henry Kissinger discussed bombing the dike network in a 1972 conversation on Operation Linebacker II, later published by Daniel Ellsberg: