Chapter 4 examines the emergence of different internationalist aspirations on both sides of the Atlantic to supersede conflict-prone imperialist power politics and to advance towards a more pacific international order in the decades before the First World War. It compares the pursuits of liberal and both centrist and more radical socialist actors, non-governmental associations and newly important transnational networks like the burgeoning pacifist movement, the Second International and, notably, the new phalanx of those who demanded that power politics should be replaced by arbitration and authoritative covenants of international law – and who paved the way for the Hague Conventions of 1899 and 1907. It reassesses not only the guiding ideas of the vanguards of such aspirations but also the actual influence they had on transatlantic and global politics in this crucial phase, seeking to offer a systematic explanation of why these counterforces failed to civilise international politics and why ultimately they could not prevent the escalatory processes that caused the catastrophe of 1914.