Sure, 2008 was bad. But for Americans it was nowhere near as bad as 11,000BC – according to research published in Science magazine yesterday.

At about that time, say scientists, a massive comet struck the atmosphere somewhere above North America, broke into pieces and rained down fire and death – wiping out the early Palaeo-Americans, also known as Clovis people, and making creatures such as the woolly mammoth, mastodon, short-faced bear, sabre-toothed cat, ground sloth and giant armadillo extinct. Not to forget the American camel and the American lion.

Although this theory first emerged a year ago and has been hotly debated ever since, the authors of the Science article present compelling evidence to support it – in the form of nanodiamonds.

These, which are so small they are barely visible even under the most advanced microscopes, have been found embedded in 13,000-year-old sediment in North America and Europe. The only plausible explanation for this, say the authors, is a planetary catastrophe of the sort that bade farewell to the dinosaurs about 65 million years earlier.

Previously secret papers released at the National Archives show how James Callaghan, the Labour prime minister, was informed in August 1977 of a secret test site in the Kalahari Desert in a personal letter from Leonid Brezhnev, the Soviet president.

A Soviet spy satellite had discovered the site at Vastrap, in a remote area south of South Africa's border with Botswana, a week earlier. Two 750-foot shafts had been drilled in preparation for underground explosions. The Americans appear to have possessed similar satellite imagery but failed to inform their closest ally until after the Brezhnev letter.

In his letter of 8 August, the Soviet leader said he wanted to draw Callaghan's attention to a matter of "very great importance". Citing "available information", he went on to identify the Kalahari site and called on the British to exert pressure on Pretoria to cancel its clandestine programme.

The Vatican City State, the world's smallest sovereign state, has decided to divorce itself from Italian law.

Vatican legal experts say there are too many laws in Italian civil and criminal codes, and that they frequently conflict with Church principles.

With effect from New Year's Day, the Pope has decided that the Vatican will no longer automatically adopt laws passed by the Italian parliament.

White House Chief of Staff Joshua B. Bolten and national security adviser Stephen J. Hadley remember conferring with President Bush during the darkest days of the Iraq war, in 2005 and 2006, when violence was out of control. In daily 7 a.m. meetings in the Oval Office, Bush reviewed "blue sheets" detailing incidents involving U.S. soldiers; he would circle the casualty figures and press his top aides for details about the deaths.

"It was pretty grim news," Hadley recalled last week. For him, however, the sessions underscored the president's focus. "This notion that somehow the president didn't know what was going on, information was withheld from him in some way, he didn't have a picture of what was going on: He got that picture" -- Hadley smacked his palms together for emphasis -- "at 7 o'clock every morning."

Few officials have had a closer view of the Bush presidency over the past eight years than Bolten and Hadley, who are among the handful of senior staffers who entered the White House with Bush in 2001 and will exit with him on Jan. 20...

Last week, in lengthy interviews in the spacious chief of staff's office in the West Wing, Bolten and Hadley reflected on their White House years and painted an affectionate portrait of the president. As two of the top officials who have had to defend controversial administration policies for the duration of the Bush presidency, they voiced frustration over their inability to improve Bush's popularity and to counter the administration's image of arrogance. But in a wide-ranging conversation lasting more than two hours, the two men also rebutted what they consider common misconceptions of the George W. Bush era, such as the president's alleged insulation from bad news and the view that Vice President Cheney wielded unbridled behind-the-scenes power.

"One of the mythologies," Hadley said, "is that it was the vice president that somehow was pulling the strings on foreign policy in the first term and made it very ideologically driven and that somehow in the second term, the vice president's influence is in decline and, therefore, somehow the real Bush has come forward, and we have a more pragmatic foreign policy."

"That's just hooey -- it's just hooey," the ever-polite Hadley concluded, with the strongest language he would muster for print...

Helen Suzman, the internationally prominent anti-apartheid campaigner who befriended the imprisoned Nelson Mandela and offered an often lonely voice for change among South Africa's white minority, has died, South Africa's SAPA news agency reported on Thursday. She was 91.

Suzman was for many years among the most venerated of white campaigners urging an end to the injustices of racial rule. But, while she challenged apartheid, her views on the creation of a new society fell well short of demands advanced by more radical black campaigners for such measures as economic sanctions to pressure the country's white rulers toward reform.

A diminutive, spry and elegant politician, Suzman became her country's longest-serving legislator, pressing for changes from the benches of the whites-only Parliament for 36 years before she retired from the assembly in 1989 and later created a pro-democracy foundation named after her.