Although World War I witnessed combat in Africa, the Mediterranean and Eastern Europe, the Western Front in France and Belgium was the conflict’s key land-based battlefield. Fighting began here in August 1914 and continued for more than four years until the signing of the Armistice on November 11, 1918. Allied victory over Germany and the other Central Powers resulted from the breakthrough advance made on August 8, 1918, which was itself the result of several different events.

German Attack in March 1918

On March 21, 1918, the German army launched an attack they called “Operation Michael.” The assault was on a huge scale and punched through the Allied defensive lines, moving the German front line around 40 miles west and throwing the Allies into retreat. Although in that sense, the attack was a success, the Germans sustained losses of 348,000 men in just over a month, ultimately leaving the German army weakened and exhausted. By the summer of 1918, most German soldiers realized that they could not win the war, and desertion rates rose.

American Involvement

The United States formally entered World War I as one of the Allies in April 1917, but American troops did not arrive in Europe in significant numbers until 1918. They took part in their first action in the Marne area of France in May 1918, and by the end of June an estimated 10,000 American troops were arriving in Europe every day. The U.S. Army did not win the war for the Allies but its arrival, at a time when the German army was in a weak and demoralized state, strengthened the Allied position.

Tactical Advances

By 1918, the Allies had learned the lessons of four years of warfare, and advances in technology were put to good use, argues Gary Sheffield of the University of Wolverhampton. When the Allied soldiers advanced in the summer of 1918, they did so accompanied by tanks, sophisticated artillery barrages and aircraft performing reconnaissance, ground attack, bombing and artillery-spotting roles. For example, when three American Corps – 600,000 men – advanced against the Germans on September 26, 1918, they were supported by 189 tanks, 821 aircraft and 2,700 artillery pieces.

Command Structure

Changes in the Allied command structure also contributed to the breakthrough on the Western Front. Prior to March 1918, the French and British armies on the Western Front were under orders from their own commanders. This command structure contributed to German success on March 21, because the British commander, Douglas Haig, and his French counterpart Philippe Petain each maintained their own priorities. In May 1918, the French and British governments agreed to hand French General Ferdinand Foch overall control of the Allied armies, streamlining the decision-making process and ultimately contributing to the Allied victory.