I just spent some time today watching the History Channel regarding World War I and World War II. One very interesting thing that happened was that while completing an order to deliver a message, from one German trench to another trench. In World War I a runner of messages from trench to trench was the most dangerous assignment and most were killed doing so.
This one runner was dropped along the path to complete his mission due to an exploding shell in close proximity to him however it was not a fatal wound in fact it he was not injured at all and as he got up to continue to the trench to deliver his message he looked to his left only to see an Allied soldier with his rifle pointed directly at him. For whatever reason the English soldier had mercy on the German soldier in this moment, maybe he felt there had been enough fighting and killing, maybe he felt it wasn't a fair fight. For whatever reason maybe he just wanted to save one life that was in his hands that day.
The crazy thing though was that the German soldier given his life to him that day, when it just as easily could have been taken away, was Adolph Hitler. If that English soldier had of taken the shot and killed Hitler that day imagine the changes to history that one shot could have made. Would there have been a World War II? Would there have been an Atomic weapon developed, Nuclear energy? No one could really, accurately, guess what the future would have been had that soldier fired that shot but imagine his remorse through the years of World War II knowing that he could have killed Hitler that day and how many lives along with that shot he could have saved by just taking one life.
Just one of histories little quirks and chance occurrences.