The international landscape looks radically different at the beginning of 2009 from a year earlier, and not just because Barack Obama is moving into the White House. The biggest problem he faces is one which will affect every corner of the world: the threat of the worst economic downturn since the Great Depression of the 1930s.
Quite apart from the job losses and bankruptcies which are already beginning to affect most economies, there must be the fear that the crisis could create new conflicts, and worsen existing ones. Russia and China are two countries where breakneck economic growth has engendered strident nationalism; their mood could grow more aggressive as demand declines for their exports – of gas, oil and minerals in the case of the former, and of manufactures by the latter.
Countries such as Ukraine, where Moscow's annual threat to cut off gas supplies is already being uttered, will be wary of falling victim, as Georgia did, to Vladmir Putin's desire to show that Russia is a power to be reckoned with. Similar caution could be shown by territories considered by China to be its sovereign business. Taiwan falls into this category, and so does Tibet. The Dalai Lama's recent suggestions that he will step back from a political role, leaving the question of his homeland's future to a younger generation of Tibetans, makes it hard to see how progress might be made in the next 12 months.
Economic strictures are likely to dull Western countries' appetite for new peacekeeping missions – in Zimbabwe or Somalia, say – or for reinforcing existing ones, notably in the Democratic Republic of Congo and Darfur. As ever, the downturn is likely to hit the poor countries of sub-Saharan Africa the hardest, just when flows of aid money are slowing and sterling's decline means that our assistance goes less far. The UN World Food Programme, for example, which is trying to feed more than half the people in Zimbabwe alone, has just called for a record injection of $5.2bn (£3.4bn), because grain prices are high and the number in need is growing. But it struggled all through 2008 with a worsening shortfall in its funding, and 2009 is unlikely to be any better.
The most dangerous area of the world will remain the "arc of crisis", stretching from north Africa to south Asia, but the hottest spots within it could change. Whether you consider it "mission accomplished" or a humiliating retreat, we now know that all of Britain's 4,100 troops will leave Iraq by the summer, apart from some 400 helping to train the Iraqi army and navy. American troops are to pull out of Baghdad and other Iraqi cities by the end of June, the first stage of a withdrawal due to be complete by the end of 2011.
Iraq may or may not become a more secure and stable country after the occupation ends, but attention will swing to Afghanistan and its equally dangerous neighbour, Pakistan, where al-Qa'ida has taken refuge and the Taliban prepares its attacks on Nato forces across the border. One of the main planks of Mr Obama's election campaign was the need for a strategic switch from Iraq to Afghanistan, and the head of the US military, Admiral Mike Mullen, has already announced that 20,000 to 30,000 more US troops will be sent there in 2009, almost doubling the American force.
The US will call on its Nato allies to send more troops as well, and Britain has indicated that its contingent could rise from 8,000 soldiers to around 10,000. But there are increasing doubts that simply pouring more troops into Afghanistan is the answer. Though the Taliban insurgents know they cannot defeat Nato in a conventional fight, they are taking a steady toll of British and other foreign troops with suicide attacks and vehicle bombings. Their ability to intimidate the Afghan population remains almost unimpaired by Nato's presence, while the rising toll of Afghan civilians unintentionally killed by foreign forces, usually in air strikes, saps local support.
Not all of the billions in development money has been squandered. But Afghanistan's rehabilitation has been crippled by the corruption and ineffectiveness of Hamid Karzai's government, which is fatally dependent on the support of former warlords whose greed and brutality spurred the rise of the Taliban in the first place. Added to this, the profits made by all factions from the exploding opium trade have poisoned governance at every level. It is not an encouraging backdrop for the presidential and provincial elections due to be held in the third quarter of 2009.
But at least Afghanistan does not have nuclear weapons, unlike Pakistan, where the government is faced by a domestic insurgency growing in boldness. President Asif Ali Zardari lacks authority, having obtained the post only because his wife Benazir Bhutto, the heir to her father's political mantle, was assassinated by Islamist militants. Mr Zardari, if he survives, is presumed merely to be keeping the office warm for his and Benazir's 20-year-old son, Bilawal, who is already president of the family's Pakistan People's Party. Such dynastic politics scarcely serve a country where the economy is in trouble, the army is always presumed to be on the brink of seizing power, and the tribal areas are a haven for extremists. Not only is their influence spreading at home, but the terrorist attacks in Mumbai, launched from Pakistan, have shown that they can provoke neighbouring, nuclear-armed India as well as Afghanistan.
According to some diplomats, however, 2009 could be the "year of Iran". During the next 12 months the country is expected to become capable of producing nuclear weapons, and the world does not appear to have much idea how to stop it. Further sanctions are inevitable, but more as a way of showing international disapproval than for their deterrent effect.
President Obama, like his predecessor, will have to deal with warnings from Israel that it might have to take military action against Iran's nuclear threat if America fails to do so. Nor can he expect the question of Israel's relations with the Palestinians to become any less of a problem. It is unclear who will succeed Prime Minister Ehud Olmert, who is due to step down in February amid a corruption scandal; a ceasefire with Hamas in Gaza has just broken down; and the split among the Palestinians, with President Mahmoud Abbas's Ramallah-based government controlling only the West Bank, remains unbridgeable.
In Europe, the hyperactive French presidency of the EU, which has seen President Nicolas Sarkozy seek to get involved in everything from Georgia's conflict with Russia to the crisis in DRC Congo, will give way to what is likely to be a more phlegmatic six months under the Czech Republic. Sweden follows in the second half of 2009, when the main European political event will be September's German elections.
In Latin America, the economic slump might strengthen Venezuela's noisy president, Hugo Chavez, and his attempts to forge an alliance with other left-wing leaders in countries such as Bolivia and Ecuador, though President Obama will make a less satisfactory bogeyman than his predecessor. It is even possible that the new US administration might at last make peace with Mr Chavez's other great ally, Cuba.
Can one at least hope that 2009 will see the fall of Robert Mugabe? With starvation and cholera wiping out his people, Zimbabwe's economy in complete collapse and inflation reaching historic heights, one would imagine that he cannot see out another year. But famine and decay have not prevented the Burmese or North Korean regimes notching up decades in power, so it cannot be taken as a foregone conclusion. Much depends on South Africa, where Jacob Zuma, who has spoken out strongly on Zimbabwe, is expected to take over the presidency from Kgalema Motlanthe after elections due between April and June.