It is highly likely that the next global conflict will be over resources, you only need to look at events in the last 50 years to see how oil has (directly or indirectly) sparked conflicts. In fact one of the most urgent issues is actually fresh water - the first 'water war' was actually fought only a decade or so ago...
It seems we didn't learn a lesson from the first or second one. Everyone is in a war for power. I have no idea why we can't be satisfied with what we have, and why we can't just get along. But there is an incredible power struggle between the countries, and that can only lead to war.
There will most likely be a Third World War, just probably not anytime soon, or right around the corner. I think it is safe to say that there will always be wars, and conflicts, because it is just human nature and a part of life. Not everyone is good, not everyone is bad.
A third World War is just a matter of time. It could happens a few years from now, or it can happen hundred of years from now, but at some point history will turn around and repeat itself like it always does. Only time will tell us at what point this will happen.
In my opinion there will be a third World War. That does not mean it will happen anytime soon though. The third World War could happen years beyond this point in time, even decades, but eventually history repeats itself and the earth will go through a third World War. Hopefully not any time soon though.
If we're talking about North Korea, then no. North Korea have tried to pull crazy stuff because South Korea have had a new president before. And they're not stupid, they no that if they do any sort of attack on America, they will most likely be wiped off the map because you don't go messing with economic giants.