There is no such thing as a zero percent chance of anything.. Maybe really improbable, but never zero. I believe there is math to back me up here ?
Everything happens for a reason and eventually turns out to be okay?
Nuclear weapons still have the potential to destroy the entire world.
Can you point out anything positive about the extreme regime in Iran?
Did the second world war help anyone?
How about 9\11?
Chernobyl?
Nuclear weapons have taught us about the horror of war. They have maybe even kept a war from occurring ? The science behind them has been useful. Its also hard to see the long term ( 1000 years ) outcome of the bomb. Maybe it will teach us a serious lesson. It sure seems to have taught you a serious lesson
Iran. Not completely sure yet. We are too close to the event in time. Its really more about religion. It might ultimately teach us something about how religion should not control a government. Thats a lesson for the US government as well in fact.
Second world war... Well again the lessons from it were numerous. Yes I think we learned a great deal from it.
9/11 had all sorts of positive effects. It may have kept a MUCH larger terrorist threat from occurring that would have killed MANY more people..
Chernobyl.. Taught us about how dangerous nuclear power really was. Helped cause the fall of the USSR.
Also your discussing things in a 50 year period.. Its just a tiny sliver of a 1000 year history. In a 1000 years the events your discussing may have resulted in changes we cant see now. They may have much different meanings with the passage of time..
Your examples are good ones. In each case the outcome would not have occurred without it being a very dramatic event. Sometimes dramatic events are needed to obtain a result.
YES I see all those events as having a good reason to have happened..