Read the history, Nixon began the withdrawal/disengagement process nearly as soon as he came into office in January 1969, Vietnamization! All the bombing that he was vilified for was a covering action and action to stop the resupply of NVA forces attacking during the withdrawal of US ground forces. It was also a negotiating tool in trying to reach an agreement to end our war with North Vietnam.

By the time Nixon resigned in August of 1974 the Paris Peace Accords had been signed over a year and a half before January 23 1974.