haha I love this! People are severely misinformed about the destructiveness of nuclear weapons. They are terrible things, insanely effective at killing large amounts of people (especially modern ones which are designed to create a lattice of supercharged fireballs that descend to create a "lake of fire" - or rather an area in which everything spontaneously combusts) but they cannot make humankind extinct - they could set us back a few hundred years sure, but radiation would be back to "safe" levels within a year (for modern efficient warheads).