Contributor(s): Judge Sir Christopher Greenwood | While each system of national law seeks to regulate affairs within only one society, international law concerns the entire world. Yet it has almost none of the methods of enforcement available to national legal systems. So, can it change the world? Christopher Greenwood was elected a judge at the International Court of Justice (ICJ) in November 2008. He is an authority in international law who taught at LSE for 12 years, and was a practising barrister and has been a QC since 1999. He has appeared as an advocate in several cases at the ICJ.