This qualifies as bad news.

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 vast U.S.S. Kitty Hawk – a 1,000ft supercarrier with 4,500 personnel on board.

By the time it surfaced the 160ft 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 U.S. Navy.

The Americans had no idea 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 Adm 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.

“Because 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.”

The infiltration took place off Okinawa, so it not only threatened the US, but also one of our staunchest allies.

(h/t Chris R.)