EXERCISE WITH A CHILEAN SUBMARINE: A Chilean diesel-electric submarine conducts operations in the Pacific with the U.S. Navy’s Third Fleet. In typical DESI exercises (Diesel Electric Submarine Initiative), USN anti-submarine warfare (ASW) aircraft play “cat and mouse” with diesel-electric subs from friendly South American nations. The South Americans portray “potential adversaries” who deploy diesel-electric subs — like Iran, Russia and China.