By Paul Burnell and Andy Denwood
BBC Radio 4
From the Ming Dynasty emperors to Mao Zedong, China's military prowess has been based on large land armies.
China's defence budget far exceeds official figures say US sources
This year China is celebrating the 80th anniversary of the Peoples' Liberation Army.
But its traditional strategic thinking is undergoing a huge shift, prompting fears in the United States that China might pose a threat to American diplomatic and military power with a naval arms race in the Pacific.
The capitulation of Sadam Hussein's army in the face of a hi-tech American onslaught in Desert Storm, with land, air and sea forces enabling a rapid US advance across large areas of land, gave a fresh impetus to military modernisation, according to Christian Lemiere, China expert at Jane's Country Risk.
"China had always relied upon the idea that if attacked it had large areas of land. It could fall back with these areas but if one power is able to take that and very quickly, it rapidly negates any advantage."
China's armed forces are over two million strong
China has been looking to match US military technology and launched an anti-satellite missile as part of this process.
Joseph Lin, a military affairs analyst with the Jamestown Foundation in Washington said this development has unnerved the Pentagon.
"The United States is heavily dependent upon satellites for all matters of communications, especially the military, which would be crippled and completely ineffectual without any sort of satellite coverage either for imaging, navigation or for communications."
At the same time, China's naval build-up has alerted American military officials to the previously unthinkable possibility that they might face competition in the Pacific Ocean, where the US has enjoyed naval dominance since the World War Two.
Richard Lawless, Deputy Undersecretary of Defence for Asia and Pacific Security Affairs, believes it is the biggest shift in the region's power balance for more than 60 years.
And he is especially concerned with the development of new classes of submarine, including two of them nuclear: one an attack submarine class, the other a ballistic missile submarine. Since 2000 China's official military budget has leaped from $15bn to $45bn.
Some US estimates say these figures exclude a range of defence-related outlays such as arms purchases from abroad and put the true figure for China's annual military spending at up to $122bn.
Professor Yan Xuetong, director of the International Studies Institute at Tsinghua University in Beijing, and an analyst whose voice is heard by Chinese and American decision makers, said China needs submarines to deter the US Navy.
"Every major power when they increase the military budget will bring about this kind of suspicion," he added.
China's official pronouncements stress a commitment to "peaceful development".
Prof Nie Youli, of the East China Normal University, is an influential advocate of building up China's navy for economic security.
"A country that depends on sea-trading faces the greatest threat to its survival in areas outside its own borders. Because of this, we need to have a stronger navy to protect our trading interests."
Some Chinese observers feel their vulnerability is most clearly demonstrated by "the Malacca Dilemma."
More than 80% of the imported oil which fuels China's expanding economy has to pass through the narrow Straits of Malacca which link the Indian and Pacific oceans.
One school of thought in Beijing worries that if relations with the US were to break down, Washington might block the Straits and cut off its oil.
Others warn that developing a much more powerful Chinese navy capable of keeping the oil flowing might unnecessarily provoke America.
Professor Zha Daojiong, director of the Centre for International Energy Security at Renmin University, concedes that opinion is divided.
But he is not convinced by the blockade threat, pointing out that this would also hit supplies to American regional allies like Japan and Korea.
Nonetheless, China's navy is growing, with the acquisition of new missile destroyers and submarines.
This process is sparking a new arms race in the Pacific, according to naval expert Paul Kennedy, Professor of History at Yale University.
"When I was in South Korea recently I quizzed the Naval Ministry about the construction of some very large, 7000 ton missile guided destroyers. They said: 'Well look at how many destroyers Japan is building', and if you ask the Japanese Navy they would say: 'Well look how many destroyers China is building.'"
Dr John Chipman, director of the International Institute for Strategic Studies, said Japan - China's historic enemy - is also quietly strengthening its navy, which will soon be larger than Britain's Royal Navy.
This naval build-up is fuelling the debate in Washington about how the US should respond to China.
One side, seizing on Pentagon warnings, argues that the United States needs to act decisively to halt the rise of the "China threat."
Rick Fisher of the International Assessment and Strategy Centre, said: "The United States has a period in which it can expand upon its current military technical superiority and form a kind of hard basis for deterring conflict, but that requires that the United States understands that we're now in an arms race.
China says its navy is needed to protect trade interests
"The United States must invest especially in the technologies and in the science that will allow us to maintain the superiority that will impress the communist leadership in Beijing that wars are futile."
But others, like Congressman Adam Smith from Washington state, argue the danger is that the United States will create an enemy and talk itself into another Cold War.
"I see no reason that we need to view them as a military threat and to get involved in an arms race build up."
A concerned Pentagon, however, made its anxieties clear to the US Congress this spring in its latest report on China's military capabilities.
The US still has overwhelming naval superiority
No official Chinese government spokesman accepted the BBC's invitation for an interview.
However, earlier this summer, Lieutenant General Zhang Qinsheng, a senior general in the Peoples' Liberation Army responded to American anxieties at an international conference in Singapore.
He said the Pentagon report was unreliable, a product of "the Cold War mindset" and detrimental to China-US relations.
IISS director John Chipman, who chaired the conference said: "I think the majority of people in the conference were reassured by his attempt to demonstrate that Chinese defence expenditure was uniquely for self-defence, but the same majority were also certain that increased Chinese force projection capabilities ... would help China to confront - if it ever came to that - larger navies around the region which would include the United States."
You can find out more by listening to Part One of The Shadow Of The Dragon - China And The New Arms Race: Tuesday 14 August 2007 2000 BST, BBC Radio 4, repeated Sunday 19 August 2007 1700 BST. Part Two is broadcast 21 August 2007, 2000 BST and repeated Sunday 26 August at 1700 BST.