This year in review will first discuss the major developments that contributed towards the formation or enforcement of international humanitarian law. Despite the many positive developments in the elucidation of international humanitarian law, 2009 witnessed the continuation of violent armed conflict around the world, not least in Sri Lanka where the long standing armed conflict came to a bloody conclusion amidst allegations of summary executions and other serious violations of international humanitarian law. Two other conflicts involving Israel/Gaza and Russia/Georgia which took place in 2008 and early 2009, resulted in the release of two influential international investigative reports, each of which alleged serious violations of international humanitarian law and called for the enforcement of criminal accountability. The election of Barack Obama marked a significant shift in the attitude of the United States to terrorism and detention with the new President immediately announcing on taking office, the closure of Guantánamo Bay.

A continuing debate within international law research is whether there is an emerging international constitutional order. This journal devoted an issue to this discussion and there have been a number of books and articles written on the subject. Indeed, the philosopher Jürgen Habermas has recently joined the debate by writing an essay entitled (in the English translation) ‘Does the Constitutionalization of International Law Still Have a Chance?’ The essay reminds the reader of constitutionalism's original philosophical roots in Kantian cosmopolitanism. Habermas argues that the world dominated by nation-states ‘is indeed in transition towards the postnational constellation of a global society’. He contrasts this vision with the realist opinion that the taming of political power through law is only possible within a sovereign state and with a more recent view postulating a vision of a liberal world order under the banner of Pax Americana. In support of the Habermas position, it can be argued that as a result of the UN 60th Anniversary Summit's adoption of the international norm of ‘the responsibility to protect’, there is a trend towards constitutional values in our international system. As Anne Peters states, ‘[t]he most fundamental norms might represent global constitutional law.’