 Various schemes had been proposed in the years before 1965 for a defensive line on the northern border of South Vietnam and in southeast Laos.These schemes had generally been rejected because of their requirements for large amounts of military personnel to be deployed in static positions and because any barrier in Laos would encourage the Vietnamese to deploy their forces deeper into Laotian territory.In December 1965, Robert McNamara met twice with Carl Kaysen, a former Kennedy-era National Security Council staff member.