Kerry even illlegally negotiated with the N. Vietnamese, while in France in the early 70's.
I have known 3 people who's families lives where destroyed when the communists took over. They lost everything, as did millions others I'm sure.
Kerry gave the North hope that they could win the war, even though they began suffering losses that they could not continue to endure.
Lot's of people here know more about this war than myself, but I know enough to feel that Kerry did help the North.