World War I on the western front was a war of attrition, because it wore down from the usual fight above ground to what is now commonly known as "trench warfare", in which soldiers are dugged into the ground, and equipment used is used to either help them stay in the trenches or dig the enemies out of their trenches. Attrition, after all, means to "wear down". Generally whoever had the better trenches (Germany did), and whoever had the most man power, supplies & materials, and equipment, as well as the means to transport these (the Allies), would help them last longer, and in the end, win.
