The high hopes surrounding Barack Obama's Presidency are mostly a good thing, as they remind us that much of the anti-American sentiment that is so apparent around the world is not and need not be permanent.

But this anticipation is also a problem for Mr Obama, as it will be difficult - and in some instances impossible - for him to meet expectations. There will be no Palestinian state this spring; nor will there be a global climate change pact or a new trade accord or an end to poverty or genocide or disease anytime soon.

The reasons go beyond the reality that big accomplishments require time and effort. The incoming president faces extraordinary constraints - constraints that will make it essential for other countries to do more if stability and prosperity are to be the norm rather than the exception.

The most obvious limitation stems from the state of the American economy. Two million jobs disappeared in the last four months alone. The housing market continues to deteriorate. America's GDP is contracting at an almost unprecedented rate.

As a result, Mr Obama will have no choice but to devote the lion's share of his time and attention to reviving the economy. More than anything else, his success in this domain will determine the perception of his administration. Even he acknowledges that this will require him to delay fulfilling several other campaign promises.

A second constraint stems from all the crises that will greet the new President. Israelis and Palestinians are fighting a low-level war. The situation in Iraq is improving but is by no means assured. Obama may have to choose between attacking Iran's nuclear installations and living with an Iran that has the capacity to build a nuclear weapon in a matter of weeks. Afghanistan's government is losing ground in its struggle against a revived Taliban. Pakistan, which possesses dozens of nuclear weapons and is host to the world's most dangerous terrorists, could become a failed state, as could nuclear-armed North Korea. Many of these challenges are less problems to be solved than conditions to be managed.

A third constraint stems from trends in the international system. The era of American unipolarity is over. Mr Obama will inherit a world in which power in all of its forms - military, economic, diplomatic, and cultural - is more widely distributed than ever before. This means that he will have to deal with a large number of threats, vulnerabilities, and independent actors who may resist bending to America's will.

All of this will make it more difficult for the US to get things done in the world - and for Mr Obama to have any chance of meeting the expectations being set for him - without the active assistance of others. And since Mr Obama will want to meet some of those expectations, other countries had better be prepared for American requests - and pressure - that they act with the US rather than act against it or sit on their hands.

China will come under pressure to revalue its currency (now being held at artificially low levels) so that Chinese exports are more expensive and imports from others (including the US) cheaper. And China and other developing countries will be expected to do their share to reduce carbon emissions and slow the pace of global climate change.

European countries should be prepared for US calls to do more to meet the increasing security challenge in Afghanistan. At stake is the relevance of Nato in a world in which the principal security challenges facing Europe are to be found outside the Nato treaty area.

Countries of every sort will face requests to do their part to overcome hurdles to a new global trade accord. Tariff and non-tariff barriers will need to come down. Rich countries will be asked to reduce subsidies; poor countries to open up their markets.

Arab leaders that criticise the US for the perceived shortcomings of its policies toward the Middle East will be asked in turn how much more they are prepared to do to bolster the government in Iraq. Once the fighting between Israel and Hamas subsides, the question of what the Arab states will do to strengthen Palestinian moderates and to make peace with Israel is sure to arise.

Russia and China should expect enormous pressure from Obama to do more to discourage Iran from proceeding with uranium enrichment. This will include calls for greater political and economic sanctions, and conceivably even support for limited uses of military force to buttress sanctions.

This list is a long one, but it could easily be much longer. The rest of the world was often unhappy with George W. Bush, for both the content and style of his foreign policy.

Now others will find that the alternative to America going it alone or withdrawing from the global scene is real multilateralism, which requires their willingness and ability to commit resources to deal with pressing challenges. Mr Obama is likely to be more diplomatic than his predecessor, but he is also likely to be more demanding.

Factbox - Inaguration by the numbers

US President-elect Barack Obama's historic inauguration in Washington meant crunching a lot of numbers. Here is a snapshot of some of them:

• 5,000: The number of portable toilets distributed on the National Mall.

• 10,000: The number of buses that city transportation and Secret Service officials ferried people to Washington. Placed end to end, the buses stretched 85,137 kilometres.

• 240,000: That is how many tickets were distributed, free of charge, for the swearing-in ceremony on Capitol Hill.

• 55: The number of previous Presidential inaugurations.

• $8,249: The price of a seat at the swearing-in ceremony advertised by one online ticket broker.

• 850: Washington's Metro rail service said it had that many rail cars, capable of carrying 120,000 people every hour, operating between 4 a.m. and 9 p.m., yesterday.

• 8,000: Some 4,000 city police officers were deployed along with 4,000 from 96 other law enforcement agencies across the country.

• 32,000: The total number of military personnel who were on duty or on standby for the inauguration.

• 900: The number of hotel rooms which were available in the city.

© Project Syndicate, 2009. www.project-syndicate.org

Richard N. Haass is president of the Council on Foreign Relations.