As an example to illustrate your definition, do you believe that it was possible to find peace with Hitler and Nazi Germany without having to fight WWII in Europe?
I'll express my answer on the American civil war with the framing of your definition of 'fatalistic approach to history'.
I'm objecting to the statement that the civil was was inevitable. Full stop. That nothing could be done differently, by anyone, at any time, to avoid it.
To answer the question, I think the civil war was exactly as avoidable as you think world war 2 was. It’s more a question of semantics at this point, given they are unchangable past events.