I think anyone who incites world war 3 be it Putin or the west are seriously deranged.
Putin is many things but not a complete idiot, he would only use nuclear weapons as an equaliser.
The nearest we have come to nuclear Armageddon is in 1962 and the Cuban missile crisis.
Later Kruschev said in his memoirs that he would never have started WW3 because America would have wiped Russia out.
Sixty years later the Soviet Union is long gone and Russia is nowhere near the power it was, while the US is the most powerful and technological advanced nation on earth.