Watch Leonard Nimoy in a Marine Corps instructional video from 1954

Long before he played the greatest Starfleet officer of all time and directed the immortal 'Wrath of Khan,' Leonard Nimoy spent 18 months in the Army reserve. According to Military.com, Nimoy achieved the rank of sergeant and spent much of his army service "putting on shows for the Army Special Services branch which he wrote, narrated, and emceed."

Nimoy acted in the following instructional film along with future "Davy Crockett" star Fess Parker. It addressed what was then called combat fatigue, or the emotional and psychological toll of warfare. The film shows how Marine Corps psychologists were supposed to treat combat fatigue sufferers, giving a glimpse into how the wartime military of the 1950s dealt into the still-vital question of how to address the mental health needs of its troops. Nimoy appears as the first of the two Marines in the clip to undergo treatment.

This clip was made in 1954, at the height of Korean War and 12 years before Star Trek premiered on NBC.