Guile had been a member of the military fighting against Shadaloo for years, when he heard about an even more dangerous threat than Bison ― Lord Fuse. He went to a kid named Dexter to learn more about this Fuse guy and see if he could help. Dexter said that the war needed all the help they could get, but that Dark City needed someone to patrol the area for them. Dexter didn't trust the citizens who resided in the area and decided to send Guile to the city to protect it, and partnered him with Chun Li.
Both fighters agreed to the rôle and went out to protect the city. Neither minded that they had been sent for patrol duty since, to their way of thinking, they'd see action since the city needed patrolling.