both nixon and kissinger considered a plan offered by the joint chiefs of staff to be both unimaginative and lacking in aggressiveness. on 4 april, nixon authorized the bombing of north vietnam (which had been limited to reprisal raids just above the dmz) up to the 18th parallel. in order to prevent a total arvn collapse and to protect american prestige during the upcoming summit meeting with soviet premier leonid brezhnev, nixon decided to risk a massive escalation of force.