MacArthur decided to use the Joint Strategic and Operations Group (JSPOG) of his United States Far East Command (FECOM). The initial plan was met with skepticism by the other generals because Inchon's natural and artificial defenses were formidable. The approaches to Inchon were two restricted passages, which could be easily blocked by naval mines. The current of the channels was also dangerously quick—three to eight knots (3.5 to 9.2 mph; 5.5 to 14.8 km/hr)—and tides were so extreme as to prevent immediate follow-on landings. Finally, the anchorage was small and the harbor was surrounded by tall seawalls. United States Navy Commander Arlie G. Capps noted that the harbor had "every natural and geographic handicap." US Navy leaders favored a landing at Kunsan, closer to the Pusan perimeter and the KPA main axis of supply through Taejon, but MacArthur did not think landing there would produce a sufficiently decisive victory. He also felt that the KPA, who also thought the conditions of the Inchon channel would make a landing impossible, would be surprised and caught off-guard by the attack.