APRIL 6--Heavy air raids were conducted against NVN, the first since October 1968 when a halt was called on heavy raids. Since the bombing halt in October 1968 the U.S. air effort had been concentrated on interdicting men and supplies moving along the routes into SVN. Except for protective reaction strikes and a five-day operation at the end of 1971, called Proud Deep, very few heavy attack missions had been flown into NVN.

The U.S. heavy reactionary raids were prompted by a massive invasion of SVN by six North Vietnamese divisions, which, by 6 April, involved 12 of North Vietnam's 13 divisions. The objectives of these heavy raids were (1) destruction of all NVN aggression-supporting resources,  (2) harassment and disruption of enemy military operations, and (3) reduction and impediment of movements of men and materials through southern NVN.