Obama actually raises an interesting point on whether negotiating with certain adversaries is the same as appeasement. He comments that we negotiated with the Soviets even after they declared “we will bury you.”
We still do not have normalized relations with Cuba fifty years after Castro took office. He certainly is not the first head who took office by violent means. I often wonder that if a man takes your house at gunpoint, how long does he retain the property before you acknowledge that it is now his?
Negotiating with existential threats requires very shrewd diplomatic skills. Such positions can actually bestow credibility and strengthen the opponent. Unless you have a commitment to thwart their avowed aim, most likely military but it could be economic as well, such diplomacy will likely be counterproductive.
We may have negotiated with the Soviet Union, but they were defeated by our overwhelming military and economic might and the willingness to use it. Korea and Vietnam many have been military failures but they did show we were willing to commit our military, and these wars were componments that lead to the Soviet defeat.
Diplomacy without force is like music without instruments. – Frederick the Great or as the great diplomat Al Capone said, ” I can get more with a smile and a gun than I can with just a smile.”