‘President Trump appears not to care very much about the international legal regime governing the use of force,’ says Allen Weiner, Professor of International Law at Stanford Law School. ‘One can expect that if the United States, which was perhaps the leading architect of the UN Charter’s regime on the use of force, decides that states can go to war whenever they perceive it to be in their interest, other states will do so, as well.’

Weiner tells Global Insight that the future of the post-Second World War international legal order is at a tipping point. He argues that the future of the UN Charter depends on global condemnation, costs for aggressors and the ideologies of future leaders. ‘The great question is whether the current disregard for international law demonstrated by powerful states will bring about lasting change, or whether this is a temporary moment,’ he says.