nuclear war isn't going to happen
source: the cold war which lasted 45 years and look what happened that's right no nuclear war
there were some very close calls though
statistically, it will probably happen, odds increasing over time
now it doesn't mean the apocalypse, total world war.
for example it could be limited to india-pakistan, maybe a 100-200 nukes, leading to a mild nuclear winter for 10 years with a few degrees average temperature down worldwide