By Paul Reynolds
World Affairs Correspondent, BBC News website
Chinese President Hu Jintao arrives in London on Tuesday at the start of a visit to the UK, Germany and Spain, as part of an initiative by China to try to establish itself as a diplomatic as well as an economic player on the world stage.
China's President Hu Jintao is on a diplomatic offensive
Mr Hu has been a great traveller since he became president in 2003. He has been across Asia, South America and Africa, as well as several European countries. This trip confirms his intention of raising China's profile.
British officials think he has firmly established his authority and works well with his Prime Minister, Wen Jiabao, who himself is visiting Europe in December.
And the Europeans are just as keen to engage in dialogue with this rising power. If its economic growth continues, China could become the second largest economy in the world (after the US) by 2020.
Mr Hu's state visit to Britain, complete with the usual trappings of a stay and banquet at Buckingham Palace, follows one by his predecessor Jiang Zemin only six years ago. It is unusual for two state visits here to come so close to each other, and shows how important China has become.
"We need a wider bandwidth to discuss our exchanges," was how a British official put it.
The European Union and China are still circling round each other, uncertain as to their future relationship.
EU arms embargo
Mr Hu will probably press his case on the most outstanding contentious issue - the lifting of the EU arms embargo on China.
His Foreign Minister Li Zhaoxing, briefing reporters on the visit, described the ban as "political discrimination". He said: "It is a legacy of the Cold War. It is poorly founded, useless and can only be harmful. This should have been scrapped a long time ago."
Earlier this year, UK Foreign Secretary Jack Straw predicted that the embargo would go within six months, to be replaced by a strict code of conduct which would in fact still restrict arms sales.
However, this has not happened. China passed a law allowing military action against Taiwan if it moved towards declaring independence, and this put the brakes on EU action.
The UK government is nervous about taking the issue forward while it is holding the EU presidency, in view of strong US opposition and the most a British official would say about the embargo was: "We are moving towards lifting the embargo and continue to discuss it within the EU."
The rise of China has already produced vastly increased trade. Since joining the World Trade Organisation nearly four years ago, China has become an even greater exporter but is also buying more. To mark this week's visits, a British company has agreed to build so-called "eco cities", self-sustaining urban centres in China. Germany is to supply high-speed trains.
But China's greater prominence has brought problems as well. China's textile exports have already produced the "bra war" with the EU - a conflict between European manufactures keen to defend their market and retailers keen to import cheaper goods.
There is a direct link between China's economic growth and its diplomatic role.
It gets oil from Iran and Sudan. That gives it an incentive to avoid upsetting those countries. Yet, as a veto-holding member of the United nations Security Council, its support over Iran's nuclear programme and Sudan's repression in Darfur are vital for concerted international action.
So far, China has been on board, but Western countries will have to work hard to keep it so.
It is also needed to keep the dialogue with North Korea going and to establish whether Pyongyang, as it has stated, is seriously interested in giving up its nuclear ambitions.
China is a growing consumer of oil and a growing polluter, so the need to bring it into world negotiations on climate control is also vital.
There are some signs that China is aware of this need. According to British officials, it is coming under pressure from its own citizens to cut back on pollution. It is interested in cleaner technology to help it do so, including work on a near-zero emission coal-fired power station being developed in the US.
The greater power of China has perhaps led to a diminution though not to the elimination of human rights demands made on it by the West.
British officials preparing for Mr Hu's visit said that the UK "took every opportunity" to continue the dialogue, but admitted that "progress can often be seen as frustratingly slow".
This includes the issue of Tibet. Mr Hu's visit to the UK will be marked by Tibet activists. There is not expected to be any repetition of the incident in 1999 when demonstrators were rounded up - and later apologised to - by police.
"A lot has changed," said a British official. "They have brought millions out of poverty, but you are looking for systemic change in human rights."
One aspect of human rights in China is the blocking of many websites. A reader in Beijing has reported that the BBC website is available but has been blocked in the past. At the moment, he reports, BBC World TV broadcasts appear to be interfered with to the extent that the "screen and sound went off" when a reference was made to the demonstrations in London in 1999. "The language was slurred to be unrecognisable," he said, when there was reference to branch of a British university in China. "Censorship is still there," he reports.
Nervousness about China's future
There is still a certain nervousness that accompanies discussion of China's future role.
Nobody knows how its mixed system of capitalism run by a communist part will develop or even continue.
"The 'rise' of China has suddenly become the all-absorbing topic for those professionally concerned with the future of the planet," said Professor Lord Robert Skidelsky in the latest New York Review of Books.
"Focus on China is overdue," he added, concluding that the mixed government formula had "worked brilliantly" but wondering whether this "duet of Party dictatorship and economic freedom can continue."