aggressor

noun

1. The person or country that first attacks or makes an aggression; that begins hostility or a quarrel; an assailant.

   “Hitler and the Japanese generals miscalculated badly, 10 years ago, when they thought we would not be able to use our economic power effectively for the defeat of aggression. Let would-be aggressors make no such mistake today.”

2. a citizen/subject of the fictional Aggressor state

name

1. a fictional state created by the United States Army for maneuver and military exercise purposes in the 1950's

   “In recent years the Aggressor Homeland has been modifying its logistical organization and procedures in an effort to meet the requirements of mobile and fast-moving forces in modern warfare. (Handbook on Aggressor: Field Manual, United States Department of the Army, June 1973)”