From the Archives (February 19, 1971): Nixon warns Hanoi

President Nixon yesterday [February 17, Washington] held out the threat of unlimited bombing of North Vietnam to protect the dwindling United States military presence in the South from a major Hanoi offensive. Mr. Nixon reaffirmed his readiness to blast communist military with the full might of U.S. air power if necessary to crush any North Vietnamese attempt to pour troops across the demilitarised zone. “I am not going to place any limitation on the use of air power, except of course, to rule out... the use of tactical nuclear weapons,” he told a White House press conference. Mr. Nixon warned that time was running out for Hanoi to negotiate a settlement. But he declined to speculate about the possibility of a South Vietnamese invasion of the North as a follow up to the U.S. backed thrust into Laos. He told reporters in his first press conference since December 10: “I won’t speculate on what South Vietnam may decide to do with regard to a possible incursion into North Vietnam in order to defend their national security.” He emphasised that if South Vietnam’s decision hinged on American co-operation “then of course it could not be undertaken without our approval.”