The bombing campaign, which ultimately lasted two years, was intended to force North Vietnam to cease its support for the NLF, and was also aimed at bolstering the morale of the South Vietnamese.
The bombing campaign, which ultimately lasted three years, was intended to force North Vietnam to cease its support for the NLF by threatening to destroy North Vietnam's air defenses and industrial infrastructure. As well, it was aimed at bolstering the morale of the South Vietnamese. 
