Why did men not fight in World War 1?

Answer 1

During World War I, as is typical in modern warfare, a number of men of fighting age (18-35 years of age as a general rule) did not end up serving in the military. Some of these were disallowed because of physical infirmity of some kind. Still others were doing work considered to be of essential value to the war effort, even though not explicitly military. Others refused to serve on the basis of principle of some kind -- or, in some cases, because of fear.