Why does the World need Nuclear Weapons?

We all know that all the World's Superpowers have Nuclear Weapons, but why do we? Is World War III really on its way? The answer is yes. We all have Nuclear Weapons because and imminent attack from Aliens is inevitable in the near future. Us humans need some type of defense against the all powerful aliens and Nuclear Weapons seem to be the answer according to Vladimir Putin. President Obama has no choice but to agree with Putin, because Crimea is really the projected first first hit point from the Aliens; that's why Russia is taking Crimea over and the rest of the world is just getting involved so we don't die. We don't want North Korea to have Nuclear Weapons because we believe that Kim Jong-Un is associating with the Aliens, mostly due to his oddly shaped head. The Malaysian Airline that disappeared was considered the warning that the attack is coming soon.