Dear Student,
Important factor that led to victory of allies in the First World war was:
a. In 1917, US entered into the first World war after Germans attacked US cargo ship and had engaged in a submarine warfare. US joined the allies.
b. With the entry of US, there was massive increase in the amount of resources spent along with increase in manpower involved in the war.
c. The war was the first modern warfare that involved the use of chemical weapons, modern mechanised weapons, tanks etc.
d.The war was fought extensively, on both western and eastern fronts.
e. The counter offensive by the Allies in 1918 with a series of campaigns like Battle of Ameins, Albert resulted in their victory .
Regards