The People's Liberation Army has ramped up China's maritime strategy with the weekend's confirmation of PLA Navy operations within the 200 nautical mile exclusive economic zone (EEZ) around a US territory, mainland analysts say.
They say it marks China's acceptance of international norms in maritime affairs, while others view it as increasing its challenge to other powers in the region.
Mainland experts on the international law of the sea said the move suggested a significant change in China's maritime strategy and development policy, while some defence analysts said the missions ordered by Beijing significantly raised the likelihood of a confrontation between China and other regional powers.
Some analysts said the policy, revealed at the Shangri-La Dialogue in Singapore at the weekend, also belied China's repeated protestations that its intent was purely peaceful.
"At meetings like the Shangri-La Dialogue, China is always trying to explain that it is focused on moving forward in a peaceful way, but I don't think it has changed its military policy at all," said Masayuki Masuda, a China expert at Japan's National Institute of Defence Studies.
It is assumed the territory is the Pacific island of Guam, an important outpost for the US military in the western Pacific, and that the waters around Hawaii and along the West Coast of the United States are still too distant for operations by the PLA Navy.
China and the US have struggled to agree on rules for operating on the high seas amid rising tensions across the region as China's military strength grows. The other assumption, according to some analysts in the region, is that China is using her fleet of submarines to enter the US EEZ.
In the past month, Japan has detected three foreign submarines near the Okinawa Islands. Japanese officials say they know the nationality of the vessels and have made diplomatic representations to that government.
Beijing has long complained about US warships exercising their right of passage through China's EEZ. The decision to exercise the same right in America's backyard is an indication to Washington that Beijing now has the capability to do so.
A professor of international relations at Tokyo's Meiji University, Go Ito, said China's position was hypocritical because it thought of its 200 nautical mile EEZ as its "exclusive political zone and its territory".
But Zhao Yadan , a maritime expert with Shanghai University of Political Science and Law, said it was a significant development in China's maritime policy and suggested "Beijing is moving towards international norms … That says that Beijing is accepting the international norms, which emphasise the right of free navigation on the high seas," Zhao said.
Ni Lexiong , director of the university's Institute of Maritime Strategy and National Defence Policy, said it reflected Chinese leaders' "changing concept of maritime affairs following the rapid development of China's maritime industry and rising strength of its naval force in the past decade".
Ito said Japan had been watching the PLA Navy carefully for some time and he believed China would use it submarines to expand the scope of its activities in the Pacific. "The potential for a confrontation is serious," he said.
Meanwhile, General Qi Jianguo , deputy chief of the general staff of the PLA, told the Shangri-La Dialogue at the weekend that Beijing would like to "put aside" maritime territorial disputes and resolve differences through dialogue.