These armies are strong enough to maintain law and order as long as they stay out of politics; thus the revolutions can remain peaceful. That is what the United States should insist on while encouraging corrupt and repressive rulers who are no longer tolerated by their people to step aside and allow new leaders to be elected in free and fair elections.

The main stumbling block is Israel. In reality, Israel has as much to gain from the spread of democracy in the Middle East as the United States has. But Israel is unlikely to recognize its own best interests because the change is too sudden and carries too many risks. And some US supporters of Israel are more rigid and ideological than Israelis themselves. Fortunately, Obama is not beholden to the religious right, which has carried on a veritable vendetta against him. The American Israel Public Affairs Committee is no longer monolithic or the sole representative of the Jewish community. The main danger is that the Obama administration will not adjust its policies quickly enough to the suddenly changed reality.

I am, as a general rule, wary of revolutions. But in the case of Egypt, I see a good chance of success. As a committed advocate of democracy and open society, I cannot help but share in the enthusiasm that is sweeping across the Middle East. I hope President Obama will expeditiously support the people of Egypt. My foundations are prepared to contribute what they can. In practice, that means establishing resource centers for supporting the rule of law, constitutional reform, fighting corruption and strengthening democratic institutions in those countries that request help in establishing them, while staying out of those countries where such efforts are not welcome.

The writer (George Soros) is chairman of the Soros Fund Management and the Open Society Foundations, which support democracy and human rights in more than 70 countries.

In drought years, the Amazon region changes from being a net absorber of carbon dioxide into a net emitter. The scientists, from the UK and Brazil, suggest this is further evidence of the Amazon's vulnerability to rising global temperatures. They also suggest the days of the Amazon forest curbing the impact of rising greenhouse gas emissions may be coming to an end.

The 2010 drought saw the Amazon River at its lowest levels for half a century, with several tributaries completely dry and more than 20 municipalities declaring a state of emergency. Research leader Simon Lewis, from the University of Leeds, said, "It's difficult to detect patterns from just two observed droughts, but to have them close together is concerning," he told BBC News. Both droughts were associated with unusually warm seas in the Atlantic Ocean off the Brazilian coast.

A single collision between two satellites or large pieces of "space junk" could send thousands of pieces of debris spinning into orbit, each capable of destroying further satellites. Global positioning systems, international phone connections, television signals and weather forecasts are among the services which are at risk of crashing to a halt.

This "chain reaction" could leave some orbits so cluttered with debris that they become unusable for commercial or military satellites, the US Defense Department's interim Space Posture Review warned last year. There are also fears that large pieces of debris could threaten the lives of astronauts in space shuttles or at the International Space Station. The report, which was sent to Congress in March and not publicly released, said space is "increasingly congested and contested" and warned the situation is set to worsen.

Bharath Gopalaswamy, an Indian rocket scientist researching space debris at the Stockholm International Peace Research Institute, estimates that there are now more than 370,000 pieces of junk compared with 1,100 satellites in low-Earth orbit (LEO), between 490 and 620 miles above the planet.

The February 2009 crash between a defunct Russian Cosmos satellite and an Iridium Communications Inc satellite left around 1,500 pieces of junk whizzing around the earth at 4.8 miles a second. A Chinese missile test destroyed a satellite in January 2007, leaving 150,000 pieces of debris in the atmosphere, according to Dr Gopalaswamy. The space junk, dubbed "an orbiting rubbish dump", also comprises nuts, bolts, gloves and other debris from space missions. "This is almost the tipping point," Dr Gopalaswamy said. "No satellite can be reliably shielded against this kind of destructive force."

"These high prices are likely to persist in the months to come," FAO economist Abdolreza Abbassian said. The index is now at its highest level since the FAO started the measure in 1990 and higher than June 2008 when the cost of food sparked violent protests in countries including Cameroon, Haiti and Egypt. The individual group components of the index, apart from meat, all registered rises in January.

The Cereal Price Index averaged 245 points in January reflecting rises in the price of wheat and grain. This was driven higher by flooding in Australia, which is a major wheat exporter. Rises were particularly high for dairy products, up 6.2% from December. Prices were driven higher by a combination of lower supply and increasing demand in emerging economies such as China and India. The Meat Price Index held steady at 166 points despite falling prices in Europe where a large amount of animal feed was found to have been contaminated with dioxin.

The high price of food is thought to have been a factor in recent political unrest in both Algeria and Tunisia in the form of anti-government demonstrations, protests which have spread to neighbouring Egypt and Jordan. Recently, white sugar futures hit a record high because of concerns about the damage Cyclone Yasi could cause to the Australian cane crop. World Bank President Robert Zoellick has asked global leaders to "put food first" and tackle the problem of price volatility.

Commodities prices have been on the rise generally with copper hitting a record high of $10,000 a tonne. Oil was also up on Thursday with Brent crude rising to $103.37 a barrel.

He said that rising food and fuel prices in recent months had already hit poorer countries and had already led to the massive anti-government protests in Egypt and in Tunisia. Rising social and political instability within nations had become a distinct possibility he said with "dangerous" imbalances likely to sow the seeds of the next crisis.

Unbalanced recovery across countries and social strains within countries with high unemployment and widening income gaps were proving a great challenge to governments, he said. He told his audience: "We face the prospect of a lost generation of young people, destined to suffer their whole lives from worse unemployment and social conditions. Creating jobs must be a top priority not only in the advanced economies, but also in many poorer countries."

What will come next: a democratic era that might transform the Middle East or a descent into chaos that could see the rise of an Islamist order that will undo Egypt's relationship with the West, threaten Israel and give new life to radical movements across the region.

Has a grim sunset been mistaken for a glorious dawn? For days now, articulate, English-speaking members of Egypt's middle class have been reassuring the world that their protests are not about to be hijacked by Islamists. But the secular middle class, which has thrown its weight behind Nobel peace laureate Mohamed ElBaradei is disorganised and lacks a wide social base. Egypt's political future will, instead, likely be decided by the Muslim Brotherhood, which has the assets needed to conduct mass politics effectively: a million-strong membership, deep organisational roots across small-town Egypt, and a nationwide network of schools, hospitals and charities.

Founded in 1928, the Brotherhood fired the imagination of the global jihadist movement. Abdullah Azzam, Osama bin Laden's ideological mentor, was a Brotherhood leader from Jordan; the al-Qaeda chief's Egyptian deputy, Ayman al-Zawahiri, also has a Brotherhood past. In recent years, though, the group claims to have reinvented itself as a democratic party, like the Adalet ve Kalkinma Partisi, which rules Turkey. Mohamed Badei, the Brotherhood's supreme leader, has said that the party considers democratic institutions legitimate, respects laws guaranteeing the equality of women, and will protect minority rights.

But experts are divided on whether the Brotherhood has a new face, or is wearing a mask. Some have characterised the reinvented Brotherhood as the Fabians of the Islamist movement; others suggest that it has used deception to disguise its true agenda. The truth is that no one knows for certain: words alone mean little, after all, for even the most rabid theocratic leaders in Iran don't say they want to persecute women or religious minorities.

Authorities said they were surprised to learn at daybreak that no one had been reported killed by Cyclone Yasi, but cautioned that bad news could eventually emerge from communities still cut off after the overnight storm, which left several thousand people homeless.

Emergency services fanned out to assess damage across a disaster zone stretching more than 190 miles in Queensland state, using chain saws to cut through debris blocking roads. The main coastal highway was a slalom course of downed trees and power lines, surrounded by scenes of devastation: Roofs peeled back from houses, fields of sugar cane and banana shredded and flattened, once-green expanses stripped to brown soil.

"Nothing's been spared. The devastation is phenomenal, like nothing I've ever experienced," David Brook, the manager of a resort at Mission Beach, where the core of the storm hit the coast around midnight, told Australian Broadcasting Corp radio. "Vegetation has been reduced to sticks," said Sgergeant Dan Gallagher, a Mission Beach police officer. At Tully, about 12 miles inland along the storm's path, the main street was littered with twisted pieces of metal that were once house roofs and jagged shards of glass from shattered shopfront windows. Queensland state Premier Anna Bligh said one in three houses in the town of 3,500 people either were demolished by the storm or had the roof ripped off.

Tens of millions of people stayed home. The hardy few who ventured out faced howling winds that turned snowflakes into face-stinging needles. Chicago's 20.2 inches of snow was the city's third-largest amount on record. In New York's Central Park, the pathways resembled skating rinks.

The storm that resulted from two clashing air masses was, if not unprecedented, extraordinarily rare for its size and ferocious strength. "A storm that produces a swath of 20-inch snow is really something we'd see once every 50 years - maybe," National Weather Service meteorologist Thomas Spriggs said. Across the storm's path, lonely commuters struggled against drifts 3 and 4 feet deep in eerily silent streets, some of which had not seen a plow's blade since the snow started a day earlier. Parkas and ski goggles normally reserved for the slopes became essential for getting to work.

In the winter-weary Northeast, thick ice collapsed several structures, including a gas station canopy on Long Island and an airplane hangar and garages near Boston. In at least two places, workers heard the structures beginning to crack and narrowly escaped. In Middletown, Connecticut, the entire third floor of a building failed, littering the street with bricks and snapping two trees. Acting Fire Marshal Al Santostefano said two workers fled when they heard a cracking sound.

The famous freeway appeared as if rush hour had been stopped in time, with three lanes of cars cluttering the pavement amid snow drifts that stood as high as the windshields. Bulldozers worked to clear the snow from around the cars, which were then plucked out by tow trucks one by one. Rolling blackouts were implemented across Texas, including in Super Bowl host city Dallas, due to high demand during a rare ice storm.

Louis Uccellini, director of the government's National Centers for Environmental Prediction, said the storm also drew strength from the La Nina (la NEEN'-ya) condition currently affecting the tropical Pacific Ocean. La Nina is a periodic cooling of the surface temperatures of the tropical Pacific Ocean, the opposite of the better-known El Nino (el NEEN'-yoh) warming. Both can have significant impacts on weather around the world by changing the movement of winds and high and low pressure systems.

The protesters are demanding that President Hosni Mubarak, who has ruled for 30 years, step down immediately. He has said that he will serve out his current presidential term, which ends in September, but will not run for re-election. On Wednesday three people died in clashes with supporters of President Mubarak.

Hundreds were wounded as groups fought pitched battles in Cairo, in the worst violence in nine days of protests. The unrest has left about 300 people dead across the country over more than a week, according to UN estimates. Cairo's Tahrir Square has been the main focus of the protests.

Opposition supporters say many in the pro-government camp were paid by the authorities to demonstrate, and allowed into the square by the troops surrounding it. The two sides pelted each other with stones in running battles lasting for hours. Egyptian troops refused to intervene, but fired into the air to try to disperse people. On Wednesday, they called for demonstrators to return to their homes, a call which was reiterated by Vice-President Omar Suleiman.

The Chinese carried out further tests as recently as last year, however, leading to further protests from Hillary Clinton, the US Secretary of State, secret documents show. Beijing justified its actions by accusing the Americans of developing an "offensive" laser weapon system that would have the capability of destroying missiles before they left enemy territory.

The disclosures are contained in the latest documents obtained by the Wikileaks website, which have been released to The Telegraph. They detail the private fears of both superpowers as they sought mastery of the new military frontier. The "star wars" arms race began in January 2007 when China shocked the White House by shooting down one of its weather satellite 530 miles above the Earth. The strike, which resulted in thousands of pieces of debris orbiting the earth, raised fears that the Chinese had the power to cause chaos by destroying US military and civilian satellites.

In February 2008, America launched its own "test" strike to destroy a malfunctioning American satellite, which demonstrated to the Chinese it also had the capability to strike in space. America stated at the time that the strike was not a military test but a necessary mission to remove a faulty spy satellite. The leaked documents appear to show its true intentions

The warning continued: "Any purposeful interference with US space systems will be interpreted by the United States as an infringement of its rights and considered an escalation in a crisis or conflict. The United States reserves the right, consistent with the UN Charter and international law, to defend and protect its space systems with a wide range of options, from diplomatic to military."

States such as North Korea, Syria and Iran are developing long-range missiles capable of hitting targets outside the region, records of top-level security briefings obtained by WikiLeaks show.

Long-running hostilities between India and Pakistan - which both have nuclear weapons capabilities - are at the root of fears of a nuclear conflict in the region. A classified Pentagon study estimated in 2002 that a nuclear war between the two countries could result in 12 million deaths. Secret records of a US security briefing at an international non-proliferation summit in 2008 stated that "a nuclear and missile arms race [in South Asia] has the direct potential to lead to nuclear war in the world's most densely populated area and a region of increasing global economic significance. The same briefing gave warning that development of cruise and ballistic missiles in the Middle East and Asia could enable rogue states to fire weapons of mass destruction into neighbouring regions.

The leaked documents also disclose alarming details of the chemical and biological weapons programmes being pursued by rogue states such as Syria and North Korea. Syria - which backs the Lebanese terrorist group Hezbollah - is believed to be developing chemical weapons using the lethal nerve agents sarin and VX, which shut down the nervous system in under a minute if inhaled or absorbed through the skin.

In an extraordinary move, the Prime Minister has decided to give his MPs a free vote on the issue - effectively encouraging them to refuse to bow to the European Court of Human Rights.

A defeat would allow the Government to go back to the court in Strasbourg and insist it has tried, but failed to change the law - and that the democratic will of Parliament should prevail. Conservative MPs insist the time has come to draw a 'line in the sand' after decades of kow-towing to the European courts.

Government sources say it will be 'helpful' if Parliament expresses a clear view on the issue of votes for prisoners and enables ministers to insist on the 'minimum possible' change in the law.

A Koran, two crossed swords and a message: "Prepare yourselves." The crest of the Islamist Egyptian group Muslim Brotherhood is nothing if not martial. Perhaps even a bit too martial for the international press. On the first floor of a shabby apartment building on El-Malek El-Saleh street in downtown Cairo, the group - which for years has been Egypt's largest opposition movement - is receiving a gaggle of scribes from abroad. And the official symbol is nowhere to be seen.

Even verses from the Koran or photographs of the holy Kaaba in Mecca, of the kind that hang in living rooms across Egypt, are absent. Instead, visitors are confronted with desks piled high with fliers, packed bookcases and cabinets full of file folders. The message is clear: The Muslim Brotherhood is but a normal political party, right down to the business cards, water fountain and chalk board.

Just how the Muslim Brotherhood will position itself should Mubarak's regime fall is, for the moment, a matter of speculation. The group's participation in the week-old demonstrations, however, has been largely inconspicuous. There have been few Islamist banners to be seen, almost no Islamists chants to be heard on the streets of Cairo. Is the group taking a wait-and-see approach in case the demonstrations fail in the end? "Nonsense," Bayoumi said. "We are taking part. Thousands of our members are on the streets. But we are saying that this isn't a Muslim revolution. This is a revolution against Mubarak!"

The Muslim Brotherhood itself professes not to know the true extent of its support in the country. "We don't know how many members we have," Bayoumi said. "The government says three to 4 million. But we don't count. We just know that we are everywhere, in every city, every village and in every street."

The US-allied Ali Abdullah Saleh, who has been in power for nearly 32 years, spoke to lawmakers in both houses of the assembly on the eve of mass rallies that the opposition has called for Thursday in all Yemeni provinces. "I won't seek to extend my presidency for another term or have my son inherit it," Saleh told the parliament.

Saleh has earlier tried to defuse simmering tensions in Yemen by raising salaries for the army and by denying opponents' claims he plans to install his son as his successor. But that hasn't stopped critics of his rule from taking to the streets of the capital, Sanaa. In January, tens of thousands gathered in days of protests boldly calling for Saleh to step down - a red line that few dissenters had previously dared to cross here.

Saleh's current term in office expires in 2013 but proposed amendments to the constitution could let him remain in power for two additional terms of ten years. After the Tunisian revolt, which forced that country's president to flee into exile, and the mass protests in Egypt calling for the end of President Hosni Mubarak's 30 year-long rule, Saleh ordered income taxes slashed in half and instructed his government to control prices. He deployed anti-riot police and soldiers to several key areas in Sanaa and its surroundings to prevent riots. But the street protests, led by opposition members and youth activists, continued, adding to the threats to Yemen's stability.

Overall, according to the IMF managing director, widening imbalances across and within countries were sparking tensions that threaten to derail the fragile global economic recovery - and could even spark armed conflict. As Egyptian protesters gathered in their thousands demanding the departure of President Hosni Mubarak, Strauss-Kahn said: "The IMF is ready to help in defining the kind of economic policy that could be put in place."

In a speech in Singapore, he said rampant unemployment and a growing income gap was a "strong undercurrent of the political turmoil in Tunisia and of rising social strains in other countries". Nationwide demonstrations last month led to the ouster of Tunisian strongman Zine El Abidine Ben Ali, and massive street protests are raging in Egypt seeking an end to Mubarak's more than 30-year rule.

"As tensions between countries increase, we could see rising protectionism - of trade and of finance," Strauss-Kahn said. "And as tensions within countries increase, we could see rising social and political instability within nations - even war."