During the Intercorporate War, Clarkson attempts to mediate discussions between the warring General Resource Limited and Neucom Incorporated. Public criticism levied against Clarkson claims he is merely a delegate of the "older era". As the war progresses, he attempts to defect to Neucom, and his ultimate fate depends on Nemo (the player).
Clarkson completed his doctorate in international political science research at Oxform University in 2010. He later became a member of the USEA assembly, becoming an active voting member of the Neo United Nations. In 2037, Clarkson became UPEO's official delegate.
During the Intercorporate War, Clarkson and Fiona Chris Fitzgerald were part of a delegation heading towards the Meriton Highlands for an ongoing détente conference. The delegation, onboard an R-505U and escorted by Erich Jager (and Nemo, if still aligned with UPEO), came under attack by General Resource Defense Force aircraft. Rena Hirose then entered the airspace with orders to shoot down Clarkson's aircraft, citing evidence of Clarkson and Fiona engaged in espionage for Neucom. Erich later believes the order came from UPEO Special Armed Response Force commander Gilbert Park in an attempt to gain control over UPEO's military actions by killing Clarkson.
If Nemo is part of UPEO and saves Clarkson and Fiona, all three defect to Neucom. Subsequent news reports claim that Clarkson's R-505U came under attack by both General Resource and UPEO aircraft; they further state that the R-505U made contact with the Neucom Emergency Unit stationed at Dennis Airport for an emergency landing. Clarkson does not make any more in-game appearances after the defection.
If Nemo is part of UPEO or General Resource and shoots down Clarkson's R-505U, or allows Rena to do it, Clarkson and Fiona will both die in the crash. Subsequent news reports claim that the event was an accident, and SARF Commander Park publicly expresses shock and sorrow.
If Nemo is still aligned with UPEO, Park reveals in a private message to Nemo that he created the "accident" narrative for the public news reports to save face. He still claims that Fiona was involved in espionage, though Aldair Carlos Nascimento later blames Park for Clarkson's death.
If Nemo is aligned with General Resource, Abyssal Dision and Keith Bryan hint that Dision personally chose to kill Clarkson to put an end to the old world order. Dision and General Resource also claim to have known from the beginning that Clarkson would defect to Neucom.
- Ace Combat 3: Electrosphere - Mission & World View Guide Book, page 059.
- Power for Life, Ace Combat 3: Electrosphere.
- Scylla and Charybdis, Ace Combat 3: Electrosphere.
- Fates Intertwined, Ace Combat 3: Electrosphere.
- Tainted Peace, Ace Combat 3: Electrosphere.
- Reaching for Stars, Ace Combat 3: Electrosphere.