Does 'free will' exist in a cause-effect system, e.g. where a behavioral decision is always a respon
You are asking whether freedom is compatible with determinism. Here is the answer. Freedom is not about being exempt from a deterministic causal order. It is about one’s deeds being the outcome of the intentions that arose through mechanisms that were adequately rooted in one’s personality-structure. Stalin’s deeds were indeed a foregone conclusion before he was even born, supposing (as we may in this context) that the world is deterministic.
But to say that Stalin carried out those deeds ‘freely’ is to say that the mechanisms immediately responsible for them were internal to his personality-structure, and to say that they were ‘unfree’ or ‘compulsory’ is to say that those mechanisms were external to his personality-structure.
Of course, one can quibble and say that, if Stalin’s deeds were indeed the inevitable result of deterministic mechanisms, then they were not free, no matter grounded those mechanisms were in his personality. Find, but to the extent that the concept of freedom is a coherent, freedom is the ability to execute intentions whose proximal causes were personality-constitutive.