What caused Napoleon Bonaparte to loose the war?

Answer 1

Historians come up with different theories (Assuming that the War at issue is the Battle of Waterloo) ranging from hemorrhoids, to constipation, to diarrhea, to dementia, to an untrained Army, to a lack of confidence, to missed communications, to errors by subordinates, to the weather, to simple things like being out Generaled by Wellington.

Some indeed may have been a factor.

Several combined could have made a difference.

The deciding factor was the competence of the individual British trooper, the long serving and poorly rewarded Non-Commissioned Officers and the junior grade officers at the front who refused to yield ground or break after repeated attacks.

They were The Bravest of the Brave. They held Napoleon in position until Marshall von Blucher's forces could strike the French flank.