Well the cause of a certain event in history will mean something happens.
The effect is the result of the event happening
For example. With 9/11 the cause was the twin towers collapsing. The effect would have been thousands of people dying as the result of the planes being highjacked
Here is how it was explained to me. WW2 was blamed pretty much entirely in Hitler, yes obviously there were so many other factors, and decisions that made the total, destruction of everything, but everyone blames Hitler for the start of it all. In this passage though, it sounds like the blame is on the other political advisers, and his foreign minister. Like they were supposed to have pushed for more meetings, or tried to make Hitler see reason.
Hope that helps
