The short answer is yes. I think there will be war as long as the world remains a collection of sovereign nations, which will be a very long time if not forever (this statement should NOT be interpreted that I support the US ever surrendering any portion of its sovereignty to anyone, including the UN). Treaties and alliances between nations have heightened the probability that disputes will involve multiple countries.
The question of whether nukes will be used really depends on whether we will ever tolerate a "total war", the kind where every civilian gets involved. Unfortunately, there are a number of situations where we can be angered enough to commit our nation to total war. If we ever do get to that point, we will use every weapon at our disposal to guaranty security of the United States.
One interesting footnote. In all of the war gaming that I was involved in on active duty, we regularly popped nukes (computer simulated) in training exercises involving Soviet-invasion scenarios. Everyone knew that when the simulated nukes started flying, it usually meant the end of the 2-3 week training exercise and we could go home and take showers. Although the Soviet Union is now defunct, it is not a stretch to see a similar threat arising again.