I honestly do not see it happening. Most nuclear nations have conventional military forces that are easily more then capable of dealing with threats. The two most cited rogue states are basically dictatorships where the grip on power is actually more tenuous then most concede. They are likely to rattle their sabers, and nothing more. On the terror front not only are groups getting more fractured, but they are becoming increasingly localized. They simply lack the logistical ability to orchestrate such an attack.
The only conceivable scenario would be an exchange between China and India. Even then it would take a number of steps to get to that point. I am less concerned about nuclear arms, and more concerned about groups of people for the most part. Population statistics are terrifying, and it is those that raise concerns about resource shortages that will increase global tensions, and the increasing danger of truly lethal global pandemics.







