CONTROL OF SEA POWER: Allied sea powers were able to block and reduce Germany and its allies from overseas resources by limiting food supply and military service. This blockage finally forced the Central Powers to surrender.
The superiority of Weapons: The use of modern and superior weapons like the tank and others helped the Allied to achieve Victory.
Huge Material Resource and Manpower: Allied forces were able to mobilize huge, manpower and material resource as compared to the central powers
Effective Propaganda work: The Allied forces were able to persuade the world that they were fighting for the ‘right’ (as democrats) and the central powers for the ‘wrong’ (as autocrats)