Marine Corps Installations - West conducting Exercise Semper Durus 2016, a full-scale, Anti-Terrorism and Force Protection exercise, April 25 – 29 at Marine Corps Base Camp Pendleton, California. Semper Durus is a regional command post exercise that is comprised of a series of field training scenarios designed to reinforce operational response capabilities supporting MCI-West installations, tenant commands and families on base. - Marine Corps Installations - West conducting Exercise Semper Durus 2016, a full-scale, Anti-Terrorism and Force Protection exercise, April 25 – 29 at Marine Corps Base Camp Pendleton, California. Semper Durus is a regional command post exercise that is comprised of a series of field training scenarios designed to reinforce operational response capabilities supporting MCI-West installations, tenant commands and families on base.