Only one national leader -- Harry Truman -- has ever allowed nuclear weapons to be used in combat, in 1945, the same year the weapon became available. This was

Only one national leader -- Harry Truman -- has ever allowed nuclear weapons to be used in combat, in 1945, the same year the weapon became available. This was 77 years ago. He was the 33rd president, and we are on the 46th. By this measure, based only on the US, we get such a leader once every 77 years or once every 13 leaders. These numbers will only get lower once you start to add in other nuclear weapons states. That said, I don't think any of this math is pointing us toward any kind of answer about how likely any person alive right now is to experience nuclear war, which is really what we're after. At the very most, every day that nobody uses one extends the lower bound of how often they are likely to be used (77 years and counting), but this is almost tautological. Also, maybe it follows some kind of power law and the farther away from their invention, the less likely we are to use them? Or maybe the opposite? Or maybe we oscillate between the two in some sinusoidal pattern? In any case, we can't know. History is not an experimental science.