In the history of relations between the worlcfs leading states since the end of the eighteenth century certain features stand out prominently. One is that infrequent wars have alternated with long periods of peace. From the 1760s to the 1790s these states were at peace; from the 1790s to 1815 they were at war; from 1815 to 1854, peace; 1871 to 1914, peace; 1914 to 1918, war; 1918 to 1939, peace; 1939 to 1945, war; and since 1945 another 36 years of peace already. Another feature, no less pronounced, is that each of these infrequent wars has been more demanding and devastating for all participants, more nearly total, than that which preceded it. In these respects, as also in a third on which I shall enlarge later on, international conduct in the past 200 years has differed from international conduct in all earlier times, when states were more or less continuously engaged in wars that remained limited in scale – and so much so that the rise of the modern system may safely be traced back to the end of the eighteenth century.