This is off topic now but yeah the world would have been a different place if someone had listened to the demands of Ho Chi Minh earlier.. and Hammarskjöld had not been crashed

> Agreeing to end nuclear testing saved us from the Cuban Missile Crisis.

The treaty came after the crisis, not before. And it only banned atmospheric, underwater, and space tests. The US and USSR kept testing underground on a large scale, while France and China never signed it and continued atmospheric tests for years.