American military chiefs have been left DUMBSTRUCK by an UNDETECTED Chinese submarine popping up at the heart of a recent Pacific exercise and close to the huge USS Kitty Hawk, a 1000 foot super-aircraft carrier with 4500 personnel on board. By the time it surfaced, the 160 foot Song Class diesel-electric attack submarine is understood to have sailed within viable range for launching torpedoes or missiles at the carrier. According to senior Nato officials, the incident caused consternation in the US Navy. The Americans had no idea that China's fast-growing submarine fleet had reached such a level of sophistication, or that it posed such a threat. One Nato figure said the effect was "as big a shock as the Russians launching Sputnik" - a reference to the Soviet Union's first orbiting satellite in 1957, which marked the start of the space age. US Pacific Command's Admiral William Fallon says the group wasn't conducting anti-sub operations, but the fact remains that the submarine did slip past the group's security screen undetected and popped up within firing range of the Kitty Hawk. "It illustrates the primary reason why we are trying to push to have better military to military relationships with China, Fallon said." The fact is that you have military units that operate in close proximity to one another," he said, warning of "the potential for events that would not be what we'd like to see."