It was called a ““total war’’–the first industrialized war between great powers. It was marked by mechanized armies and technological warfare, but also by the elimination of age-old distinctions of battle between civilians and soldiers, cities and battlefields and day and night. Most of all, it exploded the idea of limits. Seventy million men served in the war; 9 million died in it. To put this in perspective: Americans are rightly anguished over losing 58,000 servicemen during the seven years of the Vietnam War. Yet in just the first six days of the German offensive in March 1918, British troops suffered 300,000 casualties.

By the end of the war, the center of world power had shifted from Europe to the United States. Most European states had overturned their ancient monarchies and freed many of their colonial lands. With the end of the kings came the end of an order based on divine rights and natural aristocracies. The legitimacy of the state was now based on (supposedly) rational principles–like liberalism, democracy or communism. This new legitimacy–and the emergency needs of war–brought new powers, like progressive taxation, nationalization of industries and government regulation of many elements of private life. It was, in short, the birth of the modern state.

The war muddied the great divide between social classes, and–because women went to work–began erasing the even more settled distinction between man and wife. But perhaps the most pervasive of all the legacies of World War I is the triumph of doubt and skepticism. The war began with enthusiasm. Every Englishman marched into battle with the words of Horace ringing in his ears: Dulce et Decorum est Pro Patria Mori! How sweet and noble it is to die for your country. Four years later, the horrors of trench warfare, poison gas and machine-gun slaughter had made even the bravest soldier wonder what he was fighting for.Suspicion of authority, doubts about absolutes, irony and cynicism all defined modernity, in life and art. Wilfred Owen, the English poet who died in the last days of the war, writes that had we seen the realities of war

My friend, you would not tell with such high zest

To children ardent for some desperate glory

The old lie Dulce et decorum est

Pro Patria Mori