The first presidential debate will be about foreign policy
The image of the US around the world has sharply deteriorated since the start of the war in Iraq, but the latest Pew Global Attitudes survey found that people in a number of countries believe US foreign policy will change for the better after the presidential election.
For the first US presidential debate, eight experts from around the world give their view of what the next US leader must do to restore the country's standing in the world.
Dominique Moisi, founder and senior adviser at the French Institute for International Relations (Ifri).
From Europe in general, there is the need to see the reconciliation of America with the world, a healing of the emotional gap, and an America that would give priority to the restoration of the American image.
Clearly, if the next US president were to be Barack Obama, the colour of his skin would do a great deal to change radically the image of America in the world.
Obama would be more in tune on diplomatic and strategic matters with the Europeans, though not necessarily on economic matters, where Democrats tend to be more protectionist.
But in terms of political culture, there would suddenly be a gap between Obama's America and Europe.
Suddenly America would move from a culture dominated by fear to a culture dominated by hope, at a time when Europeans would still be deeply immersed in a culture of fear. And, of course, the question is, can Obama rally the Western world behind him?
There is also a major debate in Europe about Nato.
Should Nato continue to enlarge its mission or should it return to its old mission, given the return of Russia, if not as a threat, at least as a serious problem? Why should we go as far as Afghanistan when we have to protect the Baltic republics?
Clearly there's a difference between the global vision of America and the regional one Europeans tend to have. The problem is to know if Russia today is still a global threat or just a regional actor.
The majority of French people, as well as the majority of European people, are clearly pro-Obama, partly because they are anti-Bush and they see Obama as the candidate of change. But there is also a certain element of esteem for McCain.
Zhu Feng, deputy director of the Center for International and Strategic Studies, Peking University, China.
While Chinese-American relations improved under the Bush administration and the government of Hu Jintao, President Bush remains a very controversial figure in the eyes of the Chinese people - most especially for the doctrine of pre-emption.
After 9/11 Bush proclaimed that the world had changed. Now the Chinese are wondering whether the next US president will change the world back… or change it in different ways.
Perhaps more important than his world view, the next US president will have to stabilise financial markets, deal with a weakened US dollar, high oil prices and the threat of recessionary world markets.
The Bank of China has invested heavily in America's bond market and in Fannie Mae and Freddie Mac, to the tune of $400bn. So turbulence in the financial and housing markets creates much fear in China.
In the past, presidential candidates seem to have promised starkly different visions for dealing with China. The Chinese are used to hearing a lot of over-heated campaign rhetoric - George Bush did this… but so too did Bill Clinton.
The Chinese know that policy is more important than personality. In the past, China has favoured one candidate or another, but now it cares less about who will be in the Oval Office and more about who will be able to confront important issues of mutual concern - from financial markets to instability in the Middle East.
The Bush administration's two terms laid out some very useful foundations for future US-Chinese relations - including the Strategic Economic Dialogue. Ensuring that these continue and improve is more important than the particular occupant of the White House.
Natalia Narochnitskaya, head of the Paris branch of Russia's Institute of Democracy and Co-operation.
The US needs to stop acting like a teacher to the rest of the world. Its foreign policy is so full of ideology, it's like a relic of the Khrushchev era. "All countries must follow the shining beacon of democracy." And if they don't, America gives them a shove, by force.
The next president should abandon the double standard, whereby the US closes its eyes to all sorts of faults in countries it likes, and declares them fully democratic when they clearly aren't.
He should try to get the US to manufacture more and buy less. The country's economy is deformed.
He should break with America's ideological clichés - its call to moral values, in which it identifies its own interests with the ethical and moral canon of the universe. The division of the world into good and evil is patronising and humiliating for others.
He should stop inventing conflicts every couple of years.
The US can try to exclude Russia from the G8 if it wants, it's just a VIP soiree. On the other hand, the soiree only serves any purpose because it brings together countries that play a big role in international life. So actually the G8 needs to expand. It will soon be necessary to invite China and India, which have developed much faster than America envisaged 10 years ago, when it launched its project for a unipolar world.
The next president should understand that Russia will take steps to compensate for the damage to its security brought about by deploying missile defence systems in Europe.
In the light of the recent crisis in the Black Sea region, I think it would be sensible to drop plans for Nato's expansion - to have a rest for a while.
Professor Sir Lawrence Freedman, vice-principal of King's College, London.
The United States now faces economic overstretch to match its military overstretch. Both factors are set to constrain the next president's freedom of action.
The country has far less economic tolerance than before for the sort of falls in the dollar or rises in oil price that might accompany a major conflict. Moreover, there is much unfinished business.
Iraq has improved but it is not yet secure; the position in Afghanistan is fragile, with the added ingredient of instability in Pakistan; the nuclear deal with North Korea may not stick and one with Iran has yet to be achieved; and Russia has turned bellicose.
In all of these areas dramatic shifts in policy - in either more hawkish or dovish directions - are going to be difficult to implement. Nor should one ignore the time it takes for a new president to get his bearings and his team in place.
Yet despite the widespread view that international power is now shifting away from the United States towards Asia, there are no other countries with its experience or network of partners.
Countries look to Washington for leadership, and they have become frustrated with the progressive weakness of the last years of the Bush Administration even as they were exasperated by the assertiveness of its first years.
The next president will have an international community anxious for a fresh start. The best advice: stay calm; do nothing rash; avoid commitments that cannot be backed up but also the impression that you are a soft touch; talk to anyone who has something to offer; work to build the country's bruised reputation and financial position, and to reduce its energy dependence.
And keep in mind that, whatever the intent, some big crisis will still hit you from an unexpected direction.
Ahmed Rashid, author of Descent into Chaos: How the war against Islamic extremism is being lost in Pakistan, Afghanistan and Central Asia.
The US president immediately needs to send a powerful message of friendship to the Islamic world in order to alleviate the anti-Americanism that is sweeping many Muslim countries.
This anti-Americanism, generated by President Bush's policies, is responsible for making many Muslims suspicious of democracy, human rights, political and media freedoms - which are now associated with US policy rather than with international human values.
The threat of Islamic extremism needs to be addressed in a much more holistic manner, in order to curb the spread of al-Qaeda and the Taleban in Pakistan, Afghanistan and Central Asia. Both US presidential candidates are committed to sending more troops to Afghanistan, but this would not reverse the collapse of security there or deal with the growing Taleban insurgency in Pakistan.
The regional crisis in South and Central Asia is enormous and growing daily, but there is still no internationally agreed framework to address it. Under President Bush, US policy in Afghanistan and Pakistan has been wholly militarised and conducted piecemeal.
The next US president must launch a regional political and diplomatic initiative, focusing on problem-solving dialogues to ease regional tensions - such as those between India and Pakistan, and Afghanistan and Pakistan - and direct talks with Iran. This would provide the space for Pakistan and Afghanistan to start a dialogue with insurgents who are no longer prepared to support al-Qaeda.
The initiative must be accompanied by an economic aid package that treats the region as an economic unit, to build infrastructure, trade and jobs and tackle the burgeoning heroin industry.
The next US president has to abandon ideology and hubris and reaffirm a role for the US in the global community, working with all states in a collective effort to end extremism and poverty.
Professor Samuel Schmidt, director of North American studies at El Colegio de Chihuahua, Mexico.
President Bush is seen as someone who never paid attention to Latin America. He treated Mexico as an economic market, not as a political entity or a partner, and failed to achieve an immigration deal.
I would like the next president to consider moving towards integration in the European sense - not to look at Mexico only as a market. The economic issue was resolved a long time ago. We deal with each other in a very formal framework through agreements like Nafta.
For example, we have not resolved the most important environmental issues between the two countries. The US keeps pushing contaminating plants to the southern border, which pollutes Mexico.
We don't have any deal on how to handle the supply of underground water that most of the cities in the desert get their water from.
Also, the next US president has to deal with the issue of immigration. The US receives at least 500,000-600,000 people every year from Mexico, documented and undocumented, and there is no bilateral conversation about how to deal with them.
However, immigration has not been a big issue for voters in this campaign. The candidates know that and they have been avoiding it.
The US has been accustomed for over 100 years to acting as the dominant partner in dealings with Latin America. You cannot subject countries to this kind of treatment indefinitely, so the US should not be shocked if Hugo Chavez of Venezuela looks to Russia or Europe.
The European community is now looking to have more political and economic leverage in South America - and this will happen in the next 10 or 20 years.
So I would like to see the US think about the future and how to help Latin American countries and Mexico develop, as a way to help limit immigration.
Dr Maha Azzam, associate fellow, Middle East programme, Royal Institute for International Affairs.
It is a cliche but in reality, the US cannot be blamed for all the woes of the world, or even all the woes in the Middle East.
But for the majority in the Middle East, it is seen as having failed to deliver on its promises, whether it's over the issue of a Palestinian state, security and stability in Iraq or democratisation throughout the region.
On democratisation, I would say progress has been negligible. In Egypt, if anything, we are at a standstill. Political opponents are in prison and the Muslim Brotherhood remains an illegal party even though it's committed to non-violence.
If Barack Obama pursues the line that he is willing to talk to the enemies of the US, then obviously that would raise a level of hope in the region that we may have a new US president who isn't as antagonistic towards Iran, and in turn towards Syria and others.
That would be an important gesture; however he will probably want to pursue a line that will reassure US citizens that he is more in the Bush mould - "Yes, I may offer a new face to America but when it comes to security, I am going to be as cautious as any Republican leader."
What the peoples of the region want from the next US president is some fulfilled promises, and the way a president can move on that, whether Democratic or Republican, is democratisation - more representative government and greater participation for peoples in the region.
When it comes to the issue of Israel, the US, whether Republican or Democratic, has always been a staunch ally and I don't think that's going to change.
Professor Adam Habib, deputy vice-chancellor of the University of Johannesburg, South Africa.
There are two or three major challenges for the US in Africa.
Firstly, in a lot of ways the US is under a major challenge from China. China has not only become a commercial competitor to the US, it's become a political challenge too.
For the US, foreign aid to Africa has always been tied to some notion of political conditionality, but China does not do that, so it has increased the negotiating space of African governments quite dramatically over the past few years.
China is also a major investor in the energy sector in the African continent - that also presents a major challenge to US interests because of their need for oil.
The US is also challenged by a broader scramble for the African continent and its resources. The big powers are starting to get competitive; the last time this happened the competition was mainly between the Soviet Union and the US and it created all kinds of proxy wars across the continent.
If we are committed to African development and alleviating African poverty, then we have got to avoid such proxy wars. That's absolutely crucial.
Another problem is that the militaristic approach of the US to the war against terror has serious consequences in places in Africa like Somalia.
As an African, I would want to see a foreign policy that advances trade and aid, that stabilises the continent and facilitates poverty alleviation and development - and that does mean a fundamental rethink on the war against terror.
This foreign policy must be less arrogant, more oriented towards a partnership. The US must show a willingness to talk to African governments, to recognise their complexity; it must look at a mixture of aid and trade that goes beyond simply advancing its national interest.