France wanted to recover the region of Alsace-Lorraine, which it had lost to the German Empire after the Franco-Prussian War

Great Britain saw the supremacy of its merchant navy threatened

Austro-hungarian empire and the Russian empire competed for thr control of the Balkans

Germany put the Schlieffen Plan into effect. This consisted of launching a rapid offensive on the Western Front

The Western Front between Germany and the Allies stabilised and a new phase of the war began. As they could not advance, both sides focused on defending their positions.

United States decided to join the war on the side of the Allies because German submarines had sunk neutral merchant ships.

The help of the American troops and weapons allowed the Allied forces to advance on the Western Front

Agricultural and aconsumer goods decrease

The war forced people to change their customs and take on new jobs.

The plan was rejected by the Allied countries (France, Britain and Italy), who had been devastated during four years of war. France in particular insisted on severe conditions for the defeated countries