World War I began on July 28, 1914, with the declaration of war by Austria-Hungary on Serbia, and hostilities between the Allied and Central Powers continued until the signing of the armistice on November 11, 1918, a period of 4 years, 3 months, and 14 days. The aggregate direct war costs of all the belligerents amounted to about $186 billion. Casualties in the land forces amounted to more than 37 million. Despite worldwide hopes that the settlements arrived at after the war would restore world peace on a permanent basis, World War I actually provided the basis for an even more devastating conflict. The defeated Central Powers declared their acceptance of President Wilson's 14 points as the basis for the armistice and expected the Allies to utilize the principles of the 14 points as the foundation for the peace treaties. On the whole, however, the Allies came to the conference at Versailles and to the subsequent peace conferences with the determination to exact from the Central Powers the entire cost of the war, and to distribute among themselves territories and possessions of the defeated nations according to formulas arrived at secretly during the years 1915 to 1917, before the entry of the United States into the war.

The peace treaties that emerged from the conferences at Versailles, Saint-Germain, Trianon, Neuilly, and Sèvres were on the whole inadequately enforced by the victorious powers, leading to the resurgence of militarism and aggressive nationalism in Germany and to social disorder throughout much of Europe.

The signatures at Compi è gne were ending a war that had lasted for more than 4 years. Europe was devastated: thousands of towns and houses were destoyed, the industrial factories were not functionong any more. The loss of human lives was unprecedented: 10 million of deaths, 22 million wounded people and numerous prisoners.

The civil population was constantly needed in the war. Women worked in factories, hospitals, public services for innumerable hours. People were exposed to starvation, cold weather and lack of necessary supplies. The occupied teritories suffered from economic exploitation and were obliged to support the enemy.