Why?
Because all these countries are very unstable right now. I think the first place to see nuclear weapons go off would be Israel nuking Tehran and turning it into a crater. Where it would go from there is anyone's guess.
Russia because of Putin might turn Ukraine into a Nuclear Crater at any point too or he might nuke Germany or other European countries also. Also, I think the cultural divide between India and Pakistan is very great and either country could easily nuke the other.
I think China would likely be the last country to use nuclear weapons because of the Chinese psychology which is that China has always been too big and too ungovernable and they have so many mini-revolutions inside China every year it is like 1500 mini-revolutions take place where thousands of people are wiped out by the Chinese Government and they desperately try to hide that they are killing their people by the thousands in order to continue the status quo of the Chinese Government. For all these reasons I think China is the least likely to use nuclear weapons first. So, their weapons likely are mostly for defensive purposes (at least right now). However, all this could change on a dime with today's world Conditions.










