In “The Bourne Ultimatum,” Jason Bourne has been trained to be a killer—specifically, a highly skilled covert assassin.
Bourne is the assumed identity of David Webb, a former CIA operative recruited into the secret Treadstone program. The program trains agents in surveillance, disguise, weapons, hand-to-hand combat, and precision assassination. His extraordinary ability to react under pressure comes from that conditioning, even though he later rejects the person the program made him.
The film follows Bourne as he investigates his past and uncovers the truth about Treadstone. His transformation begins after a failed attempt to assassinate African warlord Nykwana Wombosi. Bourne refuses to kill Wombosi and his children, is shot and left for dead, and subsequently suffers severe amnesia.
The phrase “a killer” is broad but accurate. “Assassin” or “CIA black-ops operative” gives more detail, while “trained soldier” is too general and misses the film’s central point: Bourne was shaped into a covert weapon.