Longest bombing campaign in US history. 990 aircraft were lost during the nearly 1,000,000 sorties flown. Largely unsuccessful due to a number of factors. The first is that civilian government officials in Washington, DC (with President Johnson at the forefront) had too much control over bombing targets and how to carry out missions. President Johnson wanted to avoid provoking Russia or China to join in the war, and so often limited actions of the military men carrying out the bombing runs. Additionally, there were many halts to the bombing meant to give the North Vietnamese a chance to come negotiate. This greatly reduced effectiveness. Second, the agrarian nature of the country made it less susceptible to the bombing of industrial centers (a tactic used with much success in WWII).