Is there a difference between Law and Morality?

This question points to the clash between legal positivism and natural law theory. It can be interpreted in two different ways. The first interpretation would consider whether there is a requirement that all laws be moral such that an immoral or 'unjust' law would not actually be law. If one chose to answer the question based on this interpretation, one could mention the Radbruch thesis which argued that the judges in Germany could have prevented the rise of Nazism. In response one could mention the argument of HLA Hart that the Radbruch thesis obscures the clash between justice and legality. Furthermore one could bring up the anti-democratic and potentially chaotic consequences if judges were able to disregard laws that would be perceived to be immoral. 

The second interpretation would consider whether law itself is a moral idea. Fuller's and Simmonds' argument that the rule of law ensures freedom as independence from the power of others could be brought up. Alternatively John Finnis' argument that law allows for the realization of the common good could be brought up as well. In response one could bring up the arguments of Hart and Kramer that the rule of law is simply a matter of efficacy rather than morality and that it is compatible with great iniquity.