God hardened Pharaoh's heart by not judging him. One of the functions of the Law is to warn us of our sin. When God withholds His judgment, He is withholding the means of Grace which we might repent if given.
Sin creates artificial man and an artificial society. This doesn't mean they aren't real, but that they cannot exist for long, because the ethic destroys itself. The judgement is "pre-built" in.