I guess time moves on. Is this any different than our relations with Japan, Germany and the rest of Europe after WWII or Eastern European countries after the Cold War? I bet the emotions are there. Notice he is not going to Hanoi at this time, the memory is too fresh. Saigon is more like "our terriroty". Sometimes we have to be nice to people we do not like or did not like for our benifits, get favors from the country, perhaps to operate air bases, spy on China or what ever. Don't have to love it just tolerate, never forget the ghosts that remain there.
He is not going to Ha Noi at this time because these things are done in stages. Along with the whole rapprochement thing is some heavy pressure to reform the system, to release political prisoners and to ease up on treatment of the minorities, and especially to introduce a Rule of Law. Each substantial level of improvement is rewarded by a higher level contact and more support for things like WTO entry. Viet Nam is very sensitive to American pressure.
Well yes, we whipped those others, or where on their side to begin with, even though they were occupied by the Evil Empire. The Communist Vietnamese we beat on the battlefield, but lost the war on TV and in the Halls of Congress.