In 1980 statesman Harold Macmillan, reflecting on the peaceful start of the 20th century, said: “Everything would get better and better. This was the world I was born in. . . . Suddenly, unexpectedly, one morning in 1914 the whole thing came to an end.”

“The 19th century’s faith in progress received its fatal blow in 1914. The year before the outbreak of war, Danish historian and politician Peter Munch wrote optimistically: ‘All evidence is against the probability of a war between the great European powers. “The danger of war” will also disappear in future, as it has done time after time since 1871.’