The year 2020 marks the seventy-fifth anniversary of the establishment of the United Nations Organisation, the cornerstone of the post-war international order, and the fiftieth anniversary of the 1970 Friendly Relations Declaration, which provided the canonical formulation of seven foundational principles of international law. Yet, the current international context seems largely inauspicious for genuine celebration. Although the world order engineered by the victorious powers after the Second World War has faced daunting challenges in the past, what is particularly disquieting about the present situation is that the challenges come, to a significant extent, from the main proponent and guarantor of the post-war rules-based international order, the United States, in the absence of any comparable stabilising forces. Whether it is the inward reflexes and blame game of major countries in reacting to a global pandemic, or the use of force by Russia for the annexation of Crimea or its interference in electoral processes in the United States, France, Italy and the UK, or the trade war triggered by the United States against China and the EU, or its withdrawal from the Paris Agreement on Climate Change, or China’s defiance of the basic rules of the law of the sea to assert its power within a ‘nine dash’ line in the South China Sea, all these cases go beyond mere controversy over the applicability of a principle to a given situation and constitute open defiance of the letter and/or spirit of the very principles that have served, since 1945, as the normative standards determining the lawfulness of international action.