China’s Xinhua news agency reported that a PLA Navy destroyer and two frigates exercising in the Western Pacific earlier this year were practicing maritime confrontation, open-sea mobile combat, law enforcement and open-sea naval commanding.

“Make no mistake, the PLA Navy is focused on war at sea and about sinking an opposing fleet,” Fanell said.

There is evidence that the PLA Navy has ambitions even beyond the Pacific.

Van Tol said China sent a frigate through the Suez Canal in 2011 to evacuate citizens during unrest in Libia, and Chinese ships have participated in anti-piracy efforts off the coast of Somalia.

According to a Dec. 10 Congressional Research Service report on Chinese naval modernization, the PLA Navy comprises 275 vessels: 75 warships, 60 submarines, 55 amphibious ships and 85 small missile boats. The U.S. Navy’s current strength is 285 ships and submarines.

Despite the similarities in numbers, Van Tol said it’s hard to compare the navies. A vessel that the Chinese might describe as a “frigate” might not be deemed worthy of the class in the U.S., he said, but added: “They have certainly been building at a vigorous rate.”

China has a large commercial ship-building industry capable of producing high-quality vessels.

Some of its latest naval designs, such as the Lanzhou-class destroyers, are equipped with powerful radar. Since 2004, the Chinese have launched more than 80 new Houbei-class missile boats, and they are acquiring increasingly advanced diesel submarines, Van Tol said.

Ralph Cossa of the Pacific Forum in Hawaii said China’s submarine fleet is the best that Russia will sell or can be copied. But he added: “The Russians aren’t selling their very best to China.

”China’s anti-submarine warfare capability remains weak, said Lyle Goldstein, an associate professor in the China Maritime Studies Institute at the U.S. Naval War College in Newport, R.I.

The Chinese have mounted a massive research effort to improve their sonar capabilities but will likely lag at least two decades behind the U.S. and its allies, he said.

“Certainly for the next decade there is a major gap to be exploited,” he said. “We need to make the investments today to keep that gap in play.”

U.S. attack submarines have the firepower and survivability to be a strong deterrent and should be spared from budget cuts, he warned.

“I think we could do with fewer carrier battle groups and putting that money towards attack submarines fleet, which is of primary importance,” he said. “That is America’s sharpest weapon.”