History shows that major wars often come completely unexpectedly.  

For example, in 1914, the Austro-Hungarians decided to launch a punitive strike against the Serbians, and it resulted in 20 million dead and Russia going over to the Bolsheviks.   Then, of course, 20 years later, Germany decided they wanted a rematch, and we got another 50 million dead, the development of nuclear weapons, and the cold war.  All because some obscure Serbian terrorist group decided to assassinate the heir to the Austro-Hungarian throne.  And that wouldn't have happened if the limo driver hadn't made a wrong turn.  

Little pivot points in history.  Imagine if some worker at a defense plant went out with his friends, got drunk, came to work hung over, made a mistake, and as a result a precision guided weapon landed on a Russian air base instead of the target it was intended for.  

The other day, Russian state media warned their people to prepare for a nuclear war.   I hope all these national leaders know what they're doing.

---