God hardened Pharaoh's heart

I've always had trouble with the concept that God hardened Pharaoh's heart. My study Bible points out that Pharaoh hardened his own heart first, and that God was just responding to that, which I guess helps some. But it still doesn't allow Pharaoh to realize what he did wrong. Instead God punishes him and all of Egypt for something that technically God did. That always seemed a bit unfair to me.