I want to know the answer to the following question:
What two northern Vietnamese cities did the US avoid bombing at the outset of the war?
All the background I'm provided with is that "The bombing campaigns of the Air Force were tightly controlled by the White House for political reasons, and until 1972 avoided the main Northern cities of Hanoi and Haiphong and concentrated on bombing jungle supply trails, especially the Ho Chi Minh Trail.". Is that enough to answer the question?