Conscientious Objector
http://www.militaryfreeschools.org/conscienceobject.htm
"This is a way that may protect you from fighting war if you do not believe that war is a good solution to our problems."
CONSCIENTIOUS OBJECTION AND ALTERNATIVE SERVICE
http://www.sss.gov/FSconsobj.htm
"A conscientious objector is one who is opposed to serving in the armed forces and/or bearing arms on the grounds of moral or religious principles."