Considering the fact that tensions between America and North Korea gets worse every day and the relationship between the Russians and America is dicy at best I'd say we're not to far off from a third world war. All it takes is a misplaced statement from a certain blond haired head of state and the whole world could literally go to shit.
Despite all this, I'd like to believe that the world has come a long way and even though tensions are high, everyone knows the cost of war. With the level of technological advancements that exist in the world right now, a third world war would probably be the war to end all wars with the death toll higher than any war before it.
I don't think anybody is willing to push the "destroy the earth" button just yet so even though the third world war could be close by, all the involved parties know what's at stake and will probably not want to start it.