I don't see any point of discussing the Chaos Theory. The point of the Chaos Theory is that everything around you affects how you act in different situations. If merely one sign in a busy street is missing or replaced, it could have outcome to how the individual acts, which road he takes.
This Chaos Theory makes it possible to run speculations about the future or the past, but then you'd have to include every thought that person would have, and every kind of environment he would experience, to be 100% accurate.
Therefore, applying the Chaos Theory to WW1 and Hitler, when we don't know his mind or even big details of the environment, is not the Chaos Theory but merely speculation. If Hitler went to a shop that we didn't know of, this could have changed the view of our speculations so hard that maybe the WW2 wouldn't have occured.
Argue with me, if there's anything to argue about.