Question

list the single most factor for the victory of the allies in world war 1

Answer 1

The main factor that decided the outcome of World War I in favor of the Allied powers was the entry of the United States in support of the Allies. Until that point, the war was a stalemate and not much progress was being made by either side—the Allies or the Axis powers.

In order to protect its economic assets and global influence, the US entered the war (although very late). Until that time, the war had dragged on for years and all the combatants were tired and without much hope, having lost so many colleagues, family members—and not to mention the fact that a number of these countries had lost a large fraction of their youth. US forces, on the other hand, were fresh, young and had good equipment. The large supply of soldiers that the US could commit and its economic and industrial prowess simply meant that the Axis powers had no chance to withstand US involvement. This more than anything led to Allied powers' victory in WWI.