Peter Apps and Andrea Shalal-Esa: Coastal patrols no longer enough for Chinese navy

China's unveiling of a stealth fighter may have grabbed headlines, but foreign powers are more worried about a growing naval build-up that is beginning to drive arms purchases elsewhere.

Beijing confirmed the first test flight of the J-20 jet during a visit by the US defence secretary Robert Gates, which was supposedly aimed at reducing tensions. Mr Gates said he had been told the test had nothing to do with his presence.

Analysts, however, said the move was probably aimed at impressing outside rivals and domestic public opinion.

They say Beijing seems to be focusing on building naval forces to counter US influence in China's immediate area and secure sea lanes further afield.

"They have shifted rapidly from a force overwhelmingly land-based to one where the navy is in the lead," said Nigel Inkster, a former deputy head of MI6 and now head of political risk and transnational threats at London's International Institute for Strategic Studies.

"This increasingly has to do with the need to ensure that sea lanes on which China depends can be kept open and China's growing overseas interests protected."

That unnerves neighbours with disputed sea boundaries, such as Vietnam and Japan, as well as Australia, the Philippines, Malaysia and India.

At a meeting of the Surface Navy Association in Washington this week, officers from a range of countries said that with a rapidly growing economy Chinese naval power would inevitably rise.

"There's no doubt that it is increasing and we can't stop that," said Captain Hiroshi Egawa, Japanese naval attach to Washington. "We need to keep an eye on their activities."

Mr Gates said on Saturday he was concerned some Chinese advances risked challenging US military capabilities, but Chinese officials stress they remain decades behind. Nevertheless, worries over China are increasingly driving global procurement patterns.

Siemon Wezeman, senior fellow at the Stockholm International Peace Research Institute (Sipri), which tracks global arms buying trends, said: "If you look at the sort of projects that are being prioritised - anti-submarine warfare, for example - they are areas largely ignored since the end of the Cold War."

He attributed that trend to worries over China. Officially, Beijing's 2010 military budget was $78 billion (50bn), up 7.5 per cent on the previous year - just over a tenth of US spending, which has doubled since 2001 and is estimated at over half of all global military outgoings.

But some analysts estimate actual Chinese spending to be much more, perhaps growing by up to 20 per cent some years.The US aims to cut some $78bn from its defence budget over the next five years, cutting troop numbers by 47,000 but largely continuing to spend on naval programmes.

"The wars in Iraq and Afghanistan are hugely expensive," Mr Wezeman said. "As the US winds them down, spending will fall, but worries about China will drive spending in some areas."

China's People's Liberation Army Navy might already have hundreds of vessels, but most are coastal patrol ships. Beijing is now fulfilling a long-held ambition to build aircraft carriers that could allow it to project power much further.

But it remains dwarfed by the US Navy, any one of whose dozen super carriers is seen as capable of defeating almost any other single navy.

However, new Chinese anti-ship ballistic missiles are seen as a potential threat to these, particularly in the event of a conflict over Taiwan - seen by Beijing as a rogue province.

"We've seen China posturing and doing a pretty good job with some technological developments designed to deny access to certain parts of the ocean," said US Congressman Todd Akin, Republican chairman of the sea power subcommittee of the House armed services committee.

Foreign worries over Chinese military expansion are not solely naval. Mr Wezeman said India was also building army and air force bases close to its border with China.

The US chief of naval operations, Admiral Gary Roughead, said good military-to-military relations were essential as China rose.

He said: "As the country's economy grows, their navy grows with it. The Portuguese did it, the Dutch did it, the British did it, the US did it. China is now in that process."