By Carrie Gracie
China is overtaking the world's major economies one by one. It leap-frogged Britain in 2005 and now has Germany and Japan in its sights.
China's leaders have talked about a "peaceful rise"
Its growing economic muscle is bringing diplomatic and military strength.
So should the rest of the world be worried?
Robert Kaplan, visiting professor at the United States Naval Academy, said the growth of Chinese power would affect the US, the current superpower.
"For the last 50 years the US Navy has more or less owned the Pacific Ocean as its own private lake," he said. "That is not going to hold for the next 50 years."
Mr Kaplan said the Chinese defence budget has been growing much faster than the economy in general. Spending has been closely targeted at developing missiles and buying submarines, with the specific aim of constraining the US Navy off Chinese waters.
However, Sha Zukang, China's ambassador to the United Nations in Geneva, insisted there was no cause for concern.
If you read China's 5,000-year-long history, he said, "it's not difficult to discover that China basically is a peace-loving nation".
The Bush administration came to power convinced that China was America's strategic competitor. But then came 9/11. To Beijing's enormous relief, Washington's focus shifted to terrorism, and there was less attention on China's discreet military build-up.
The US accuses China of under-reporting its military spending
Nevertheless, Pentagon planners are concerned about developments, and US Defence Secretary Donald Rumsfeld has said much of China's arms spending is being concealed.
Ambassador Sha responded strongly to the allegations. "It's better for the US to shut up," he said. "Keep quiet. It's much, much better."
This is a crucial question for China's future. Will it be just an economic superpower content to sell the world shoes and washing machines? Or will it have the military muscle to protect its new interests around the world?
After two centuries of feeling victimised by the West and then Japan, China chafes under a Pax Americana. At present it is keen to protect the economic achievements of the past 30 years and to avoid confrontation with Washington.
However, the issue of Taiwan could still provide a flashpoint. Ambassador Sha said there could be no compromise on this vital national interest. "For China, one inch of territory is more valuable than the life of our people," he said.
Most mainland Chinese I know are equally passionate about Taiwan. Nationalism has replaced Communism as the glue that holds China together.
The other key is prosperity. China is turning a nation of subsistence farmers into a 21st century industrial workforce. That has created an enormous demand for resources and much of China's foreign policy is now focussed on securing supplies, especially of oil and gas.
In Africa the impact is particularly stark. Garth Shelton of South Africa's Wits University welcomes the attention, saying there is a lot of optimism about the renewed Chinese interest in his continent.
"If we deal with the United States or West European governments they would bring a list of 33 items requiring restructuring of your democracy, your human rights issues," he said. "China would arrive and say we accept you as you are. And that's a refreshing change."
China has invested heavily and offered aid to many African countries, especially those with energy resources. It now is a major consumer of oil from Angola and gets 7% of its oil from Sudan.
Chinese investment is welcome in Africa
There is international criticism that China has blocked UN resolutions criticising the Sudanese government over actions in Darfur, and that it has helped prop up regimes like those of Robert Mugabe in Zimbabwe.
Senegalese journalist Adama Gaye, who has just written the first book by an African about China's new influence on the continent, accuses the Chinese of practicing "cynicism at the highest level".
He questions whether the investment is in Africa's long-term interests. "The moment they no longer need Africa they may disappear overnight and Africa will be left dry under the sun," he said.
Mr Gaye also voiced wider concerns that regimes would be attracted to a "Beijing Model" of economic development without democratic elections.
For Jing Huang of the Brookings Institution in Washington, this is the real threat to the West from China.
"What it really challenges is a value system. Who we are and what we want to be," he said.
However, China's problems remain immense and it needs markets and resources around the globe to sustain its economic growth. We can only hope the enmeshed interests of this century prevent the great wars of the last.
But even without armed conflict, the rise of this first giant of the global era will surely expose the developed world to the culture and values of a billion strangers. A sudden intimacy that may make both rich together, but may also make the West more vulnerable.
Carrie Grace presents "Analysis: What China Wants" on BBC Radio 4 at 8.30 pm Thursday August 17th