International travel by world leaders is mainly about making symbolic gestures.

Nobody expects President Obama to come back from China with major new agreements on economic policy or anything else.

But let's hope that when the cameras aren't rolling Obama and his hosts engage in some frank talk about currency policy. For the problem of international trade imbalances is about to get substantially worse. And there's a potentially ugly confrontation looming unless China mends its ways.

Some background: Most of the world's major currencies "float" against one another. That is, their relative values move up or down depending on market forces. That doesn't necessarily mean that governments pursue pure hands-off policies: countries sometimes limit capital outflows when there's a run on their currency (as Iceland did last year) or take steps to discourage hot-money inflows when they fear that speculators love their economies not wisely but too well (which is what Brazil is doing right now).

But these days most nations try to keep the value of their currency in line with long-term economic fundamentals.

China is the great exception. Despite huge trade surpluses and the desire of many investors to buy into this fast-growing economy — forces that should have strengthened the renminbi, China's currency — Chinese authorities have kept that currency persistently weak.

They've done this mainly by trading renminbi for dollars, which they have accumulated in vast quantities.

And in recent months China has carried out what amounts to a beggar-thy-neighbour devaluation, keeping the yuan-dollar exchange rate fixed even as the dollar has fallen sharply against other major currencies.

This has given Chinese exporters a growing competitive advantage over their rivals, especially producers in other developing countries.

What makes China's currency policy especially problematic is the depressed state of the world economy. Cheap money and fiscal stimulus seem to have averted a second Great Depression.

But policy makers haven't been able to generate enough spending, public or private, to make progress against mass unemployment. And China's weak-currency policy exacerbates the problem, in effect siphoning much-needed demand away from the rest of the world into the pockets of artificially competitive Chinese exporters.

But why do I say that this problem is about to get much worse? Because for the past year the true scale of the China problem has been masked by temporary factors.

Looking forward, we can expect to see both China's trade surplus and America's trade deficit surge. That, at any rate, is the argument made in a new paper by Richard Baldwin and Daria Taglioni of the Graduate Institute, Geneva.

As they note, trade imbalances, both China's surplus and America's deficit, have recently been much smaller than they were a few years ago.

But, they argue, "these global imbalance improvements are mostly illusory — the transitory side effect of the greatest trade collapse the world has ever seen."

Indeed, the 2008-9 plunge in world trade was one for the record books. What it mainly reflected was the fact that modern trade is dominated by sales of durable manufactured goods — and in the face of severe financial crisis and its attendant uncertainty, both consumers and corporations postponed purchases of anything that wasn't needed immediately.

How did this reduce the US trade deficit? Imports of goods like automobiles collapsed; so did some US exports; but because we came into the crisis importing much more than we exported, the net effect was a smaller trade gap.

But with the financial crisis abating, this process is going into reverse. Last week's US trade report showed a sharp increase in the trade deficit between August and September.

And there will be many more reports along those lines.

So picture this: month after month of headlines juxtaposing soaring US trade deficits and Chinese trade surpluses with the suffering of unemployed American workers. If I were the Chinese government, I'd be really worried about that prospect.

Unfortunately, the Chinese don't seem to get it: rather than face up to the need to change their currency policy, they've taken to lecturing the United States, telling Americans to raise interest rates and curb fiscal deficits — that is, to make their unemployment problem even worse.

And I'm not sure the Obama administration gets it, either. The administration's statements on Chinese currency policy seem pro forma, lacking any sense of urgency.

That needs to change. I don't begrudge Obama the banquets and the photo ops; they're part of his job. But behind the scenes he better be warning the Chinese that they're playing a dangerous game.

Krugman is a professor of economics and international affairs at Princeton University.

This article was first published in the New York Times.

Given his tough rhetoric on Darfur during last year's US election campaign, Barack Obama will face inevitable criticism over his new policy of engaging rather than bashing Khartoum's leadership.

But even opponents of the revised US strategy unveiled in Washington agree Sudan has reached a very fragile juncture. Obama had little choice but to soften Washington's approach and try something different — or risk a geostrategic and human calamity.

It's been evident for some time that if genocide occurred in Darfur, in western Sudan, six years ago — and the government of President Omar al-Bashir strongly disputes it — the term does not accurately describe what's happening there now. Although hundreds of thousands of people remain marooned in refugee camps, aid-dependent and afraid to return to their villages, the large-scale killings of 2003-04 have stopped.

UN officials and aid agency staff say the extreme violence of that period, which the US blames on Khartoum and its Arab Jan-jaweed allies, has been replaced by more traditional, low-intensity conflict involving clan-based rebel militias and criminal gangs, with occasional interventions by government forces. At the same time, an internationally sponsored peace process is in train.

A next round of talks is due in Qatar this month. Even Susan Rice, Obama's UN ambassador, who at one time advocated military intervention in Darfur, has rowed back. "Things have changed in Sudan from a year ago or two years ago, and this policy is an effort to take that reality into account," Rice said.

Yet in apparent deference to American opinion heavily influenced by Christian evangelical lobbying, the White House is sticking with the term "ongoing genocide" for now and will not ease sanctions unless its new policy elicits positive responses.

Obama's decision to opt for initially non-confrontational "incentives and pressure" to modify Khartoum's behaviour, as recommended by his Sudan envoy Scott Gration, was prompted by more than the relative calm in Darfur. Ever greater attention is now focusing on southern Sudan, where intertribal violence has killed more than 1,200 people so far this year, a toll far higher than in Darfur during the same period.

At stake is the western-backed 2005 Comprehensive Peace Agreement that ended decades of civil war — and related plans to hold national elections in April and a secession referendum in 2011. The collapse of the CPA would have major negative strategic implications for western interests in the Nile basin, the Horn of Africa and further afield.

Salva Kiir, president of South Sudan created by the CPA, wrote to Obama last month complaining that Bashir was deliberately destabilising the south by fomenting violence in oil-rich areas. Human Rights Watch recently accused both sides of failing to meet CPA obligations to downsize and integrate militias.

It said the Khartoum government had also "failed to implement peace agreement provisions on border demarcation and troop withdrawal", thereby exposing civilians to abuses.

UN envoys say the unrest threatens the return of a remaining 2 million out of 4.5 million refugees displaced by the north-south war. Meanwhile, Action Against Hunger is warning that South Sudan faces a "massive food deficit" caused by high staple prices and drought. Acute child malnutrition rates have spiked, while shortages are expected to worsen next year.

Responding to such concerns, Ghazi Salahuddin Atabani, Bashir's senior adviser, told the UN general assembly last month that Khartoum welcomed constructive international collaboration.

Renewed ethnic clashes in the south "threaten not only the stability of Sudan but the stability of the whole region", he said. Salahuddin added that Khartoum was committed to holding peaceful elections next year: "We invite the international community to support financially and materially the conduct of elections in deeds and in words."

By signalling willingness to accept these invitations to work together, Obama may exert greater influence in other areas of concern. One is the growing emergency in eastern Sudan, where thousands of refugees fleeing from war-torn Somalia and Eritrea's Stalinist government are arriving every month.

For these and other potent reasons, such as combating the regional spread of hardline Islamist ideology and challenging China's growing influence, constructive US and western engagement with Sudan makes sense to the White House. But as with Iran, Syria and Burma, Obama's unfamiliar "hugs not slugs" policy will be expected to produce results — and quickly.

Tisdall is an assistant editor of the Guardian and a foreign affairs columnist. This article was first published in the Guardian.

Barack Obama, president and Nobel laureate. Not bad for a fellow just five years removed from the Illinois Senate. But caveat victor: The president may soon regret having won this honour, and the Nobel committee may regret having awarded it to him.

First, let's dispense with the usual criticisms. Yes, the award was politically motivated.

But the Peace Prize has always sought to further a particular liberal vision in world affairs.

And sure, Obama unquestionably won more for his aspirations than his accomplishments, a fact the president acknowledged Friday, but aspiration has marked more than three-quarters of peace prizes since the end of the Cold War.

Consider the 1994 award to a trio of Middle East would-be peacemakers, or the 1996 prize to two East Timorese activists.

The real problem is that the prize can backfire against the honorees and their causes. In Obama's case, the Nobel may have the opposite effect of what the Oslo crowd hopes for. It may make Obama more inclined to escalate conflict than defuse it, to confront rather than engage.

In the past, the Nobel committee has insisted that the award advances the causes of the winners in subtle but powerful ways: It raises the profile of organisations, individuals and issues and bolsters support for peaceful conflict resolution.

Sounds great, except that the prize has rarely done much to produce sustained global media attention to neglected causes. Nor has it provided much impetus to incipient or ongoing peace processes. Worse still, dissidents and democracy advocates honoured by the Nobel committee have found themselves the targets of nervous and repressive states.

Just ask the Tibetans, who suffered a brutal Chinese crackdown after the Dalai Lama was honoured in 1989. Or Burmese democracy activists who experienced intensified harassment, imprisonment and military assault after opposition leader Aung San Suu Kyi won the prize in 1991.

At best, the Nobel Peace Prize changes little. At worst, it sets off political dynamics that produce exactly the opposite effect of that desired by the Nobel committee.

Obama is hardly a vulnerable liberal activist in an authoritarian regime. But he should be worried about how the Nobel will reverberate at home. To those enthralled with the president, the prize signals America's return to global leadership after the Bush administration. But to the growing number of Americans less pleased with Obama, the award is a warning sign.

After all, if the international community thinks so highly of him, perhaps it is because he shares their ultra-liberal agenda; perhaps it is because he cares more deeply about global causes than vital US interests.

The president has been sensitive to accusations of dovishness, and he has been eager to prove his hawkish credentials. Afghanistan is a case in point. Meanwhile, time after time on other issues, such as the economic stimulus package, health care and Iraq, he has tacked to the centre, much to the frustration of his most avid supporters.

The Nobel Prize won't make life at home any easier. Here, the award is a political liability, implying that Obama is not only a closet socialist but perhaps a peacenik as well.

How might Obama respond? He will seek to counteract that impression, as he must if he is to retain relevance in an American political environment still deeply shaped by the attacks of September 11, 2001.

Rather than release his inner dove, the Nobel Peace Prize may force him to brandish his public hawk. The administration's dithering on Afghanistan may come to an abrupt end.

Or the president may feel compelled to buck the international community on some salient issue just to show that he is more loyal to American national interests than to any cosmopolitan dream.

The Nobel committee probably imagined that the prize would propel Obama to new heights of diplomacy and peacemaking. But as the president takes steps to counter the award's political confines, the 2009 .Nobel Peace Prize may come to undermine the vision of a cooperative, multilateral, nuclear-free world that the committee attributed to him.

I don't imagine the committee, given its political tone-deafness and naivety, will ever regard the 2009 award as a mistake. But Obama may soon come to see the Nobel Peace Prize as a burden he'd have rather not borne.

Ronald Krebs's study "A Perilous Prize? The False Promise of the Nobel Peace Prize" Is forthcoming in Political Science Quarterly. The article was first published in the Washington Post.

It is only in politics where a dignitary can be invited for a meal and then be "disinvited" and "reinvited" within hours.

This is the story of President Obama and Prime Minister Raila Odinga that kept tongues wagging for the better part of the Idd long weekend. It is the stuff that makes headlines even in some of the most respected media in Kenya.

However, before I discuss the merits and demerits of highlighting such a basic matter as an invitation to dinner between two relatives such as Obama and Raila, let me revisit a more or less similar episode that took place in Rome sometime last year.

President Robert Mugabe had gone to the Italian city to address the World Food Programme summit in his capacity as the Head of State and chairman of the Common Market for Eastern and Southern Africa. Unfortunately for Mugabe, little did he know the host country, a member of the European Union, had planned a humiliating parting shot for him.

It did not help matters that at the time Mugabe's regime had become extremely violent on opposition politicians to the extent that his soldiers and supporters could unleash terror at the slightest provocation.

When Mugabe arrived in Rome with his beautiful wife Grace, Zimbabweans back home were enjoying an inflation rate in billions. Bank notes were seven to ten figures up. The economy was on its knees and millions literally starved for a day's meal.

It was this scenario that informed authorities in Rome to delete Mugabe's name from the list of VIPs for the farewell state banquet! And nobody had the kindness to tell Mugabe of this omission on time.

He learnt about it through the press! Their argument was that there was no point in lavishing the Mugabes with wines and sumptuous meals while back home he was starving his own people to death!

Therefore, if Obama had to decline to invite Raila to his dinner, he would not be the first African senior politician to be subjected to such discrimination on account of bad governance.

However, what is intriguing is why the media had to blow the Raila-Obama saga out of proportion! Why was it necessary for Raila to be invited, disinvited then reinvited to the same Obama function?

Knowing the American State Department, I don't think they were the authors of such careless diplomatic mischief. Americans are more meticulous when it comes to such matters. They decide these little things many months ahead of time.

Remember during Obama's inauguration in January, the whole world knew that foreign heads of state would not be invited but would be represented by their ambassadors in Washington. President Kibaki and Raila did not go to Washington. The few ministers who thought Americans were joking and ventured into Washington had to contend with watching the event from their hotel rooms.

What was curious were the conflicting reports from the American Embassy in Nairobi and of course our New York office. How come they were all in agreement that Raila had been disinvited only for the State Department to rubbish such rumours?

Who stood to gain if Raila was excluded from the Obama list of African Heads of State?

Isn't is normal international practice that when a head of state appoints one of his assistants or even a foreign minister to represent him or her at international summits, such an appointee is accorded the status of leader of delegation?

There is no denying that Obama has been unhappy with our government performance, especially with its slow pace of reforms. It is also true that he gave Kenya, his fatherland, a miss when he first visited Africa recently.

However, these are not reason enough for the media to drive a wedge between Kenya and the United States. In any case, Raila was in the US to attend the UN General Assembly at the request of his President, not Obama.

The way I see it, our media would do us proud if they interrogated foreign governments whenever they subject our leaders to unwarranted diplomatic fiascoes the way Western media protect their own rather than jump to the rooftops to celebrate our leaders' discomfort.

The Obama-Raila fiasco was a test case for the newly-hired public relations company in Washington.

Where was the company when Dennis Onyango, Raila Odinga's press officer, our missions in Washington and New York and the American Embassy in Nairobi were escalating the already embarrassing situation?

It made me believe in my earlier misgivings about hiring foreigners to clean up our mess.

They will never do it for anything else except cash.

The writer is a media consultant.