The Allies (Britain, France and the USA), defeated Germany in World War I for several key reasons:

Support of the USA

The entrance of the USA into the war made a huge difference to the allies because they provided fresh troops and supplies. America had not wanted to get involved in the war, but when Germany announced that it would attack any ship visiting British ports, the USA decided they had to act. By the Summer of 1918 there were about 2 million USA troops in France, about half of whom served on the front lines.

New Technology

Stalemate was broken on the Western Front by new technology, especially the tank. The first tanks were used by the British at the Battle of the Somme in 1916 but were ineffective as they got stuck in the mud. By 1918, tanks were much more advanced and were a key part of the allies' attacks.

The Naval blockade of Germany

The British navy was stronger than the German navy. They blockaded Germany ports, stopping supplies. As a result, Germany really struggled with power cuts and food shortages back at home. They also found it harder to supply their armies. This was at a time when the Allies were strengthened by extra supplies from the USA.

Better tactics

The British and French learnt from years of warfare on the Western Front. For example, they used creeping barrages of moving artillery fire which continued just ahead of advancing troops. They also used technology more effectively than the Germans, for example tanks, which became much more effective from 1917 onwards.

Year 9 Challenges and Change

Why did the Allies win WWI?