"The rule of law requires compliance by the state with its obligations in international as in national law. Here we step outside the confines of Magna Carta. It was directed to the exercise of power by the King within his realm, not with relations between one state and another. But the Rule of Law cannot stop short at national boundaries because the problems which we face in our world today - climate change, pollution, financial regulation, crime, migration - do not stop short at national boundaries. The lesson, however, is the same. As kings are subject to the law and not above it at home, so states are subject to the law and not above it in their relations with other states. On acceptance of this lesson, it might be thought, depend the peace and prosperity of the world. It is not a lesson which Magna Carta taught, but it is an extension of the principle which Magna Carta so memorably gave to posterity around the world."