When Jack Straw was replaced by Margaret Beckett as Foreign Secretary, it seemed an almost inexplicable event. Mr Straw had been very competent - experienced, serious, moderate and always well briefed. Margaret Beckett is embarrassingly inexperienced. I made inquiries in Washington and was told that Donald Rumsfeld, the Defence Secretary, had taken exception to Mr Straw's statement that it would be "nuts" to bomb Iran. The United States, it was said, had put pressure on Tony Blair to change his Foreign Secretary. Mr Straw had been fired at the request of the Bush Administration, particularly at the Pentagon.

Shortly before he was dismissed, Mr Straw went on his charming tour with Condoleezza Rice, in which they visited his Blackburn constituency. This had been given two explanations. One was that the US Secretary of State was hoping to protect Mr Straw, as a fellow foreign minister, against the undiplomatic attack from the Pentagon. She wanted to keep Mr Rumsfeld's tanks off her turf. She had found Mr Straw competent and effective. If that were so, Dr Rice lost that battle in the Washington turf war.

The alternative explanation was more recently given by Irwin Stelzer in The Spectator; he has remarkably good Washington contacts and is probably right. His account is that Mr Straw was indeed dismissed because of American anxieties, but that Dr Rice herself had become worried, on her visit to Blackburn, by Mr Straw's dependence on Muslim votes. About 20 per cent of the voters in Blackburn are Islamic; Mr Straw was dismissed only four weeks after Dr Rice's visit to his constituency. It may be that both explanations are correct. The first complaint may have been made by Mr Rumsfeld because of Iran; Dr Rice may have withdrawn her support after seeing the Islamic pressures in Blackburn. At any rate, Irwin Stelzer's account confirms that Mr Straw was fired because of American pressure.

Yesterday the Mail on Sunday went back for a second look at the story in the light of subsequent events, particularly the Israeli counter-attack on Lebanon. A US source told them that "Mr Straw's views did not find favour in the White House and its concerns were passed on to the British Government". That confirms that the Foreign Secretary was effectively dismissed by an American President.

In an address to Demos, Mr Reid will call for the public, especially ethnic minority communities, to help the police and intelligence services track potential terrorists, saying the professionals alone cannot "100% guarantee" to defeat the threat.

The home secretary will also say that the end of the cold war has been accompanied by the "reach and impact" of organised crime and international terrorism.

He is expected to say: "We are probably in the most sustained period of severe threat since the end of World War II.

"While I am confident that the security services and police will deliver 100% effort and 100% dedication, they cannot guarantee 100% success.

"Our security forces and the apparatus of the state provide a very necessary condition for defeating terrorism but can never be sufficient to do so on their own. Our common security will only be assured by a common effort from all sections of society."

As leaked to the weekend papers, Mr Reid will also say that mass migration in a globalised world is the "greatest challenge facing European governments".

While the mass movement of people provides the potential for greater wealth and opportunity, it also brings insecurity into the heart of communities, he will say.

The home secretary will say that the cold war "froze" the world into a static state in which migration was minimal, ethnic and religious tensions suppressed and national borders inviolable.

Twenty years after its end, Britons were now faced with a world in which insecurity has become "one of the highest concerns of daily living".

"That momentous scale of transition from static to mobile populations makes mass migration and the management of immigration the greatest challenge facing European governments, in my view," he will say.

The speech comes a week after the court of appeal said that control orders used to restrain the movements of six terror suspects broke human rights laws.

The court of appeal judges did not quash the system of control orders, which are used to restrain terror suspects where there is not enough evidence to prosecute them.

But they said that the orders applied to six suspects were so stringent that they broke European laws outlawing indefinite detention without trial.

Mr Reid has now issued new orders against the men which shorten their curfews from 18 hours to 14 hours a day and relax restrictions on who they are allowed to meet.

But he said that the orders were now not as restrictive as the security services believed necessary.

The Conservatives would still like to see a US-style minister for "homeland security" while both the Tories and the Liberal Democrats have urged the government to allow phone tap evidence in terrorist trials.

Fiona Lindsley, the former monitor, estimated that 46,000 people have wrongly been refused a right of appeal against a decision to turn down their visa application since she took up her post three years ago.

In her annual report, produced in November and published last month, the immigration lawyer said she believes discrimination is operating in the issuing of visas.

Officials are making travellers from poverty-stricken and unstable states justify their need to journey to Britain beyond the requirements of immigration rules.

Ms Lindsley said that she believed that thousands of potential visitors to Britain are being discriminated against on the ground that they come from states with records of generating asylum-seekers and illegal migrants.

"Visa nationals from poor, unstable, politically repressive countries which are known to generate asylum-seekers and which are presumed to generate significant numbers of illegal workers will be required to justify their need to travel beyond the simple requirement of the immigration rules," her report said.

It added: "In effect they are required to satisfy a higher burden of proof to obtain a visa than others because they meet a socio-economic profile that is believed to indicate they are a risk and provide little economic benefit to the UK if granted leave to enter." The discrimination is unlawful because there are no ministerial authorisations allowing individuals from particular nationalities to be treated differently for entry clearance into the UK.

Ms Lindsley said that she knew of no research that supported the assumption that those living in modest circumstances in poor countries posed a higher statistical risk of breaking visa restrictions. Ms Lindsley, whose three-year term as monitor ended last November, pointed out that research in Australia indicated that the largest group of overstayers came from Britain.

She highlighted a number of cases to support her arguments. A Romanian woman was said not to be entitled to a visa because she "knew the advantages of living and working/studying in UK".

A large number of Indians were refused entry clearance to Britain because their circumstances were modest even by local standards and they were well aware of the economic advantages of living and working in Britain.

She said that the bleakest instance was discovered in Bangladesh, where officials refused an application because "you have no prospects for the future in Bangladesh".

Ms Lindsley said that while Britain had made possible the international travel rights of European pet animals, the consequences of the country's current visa policy was to prevent thousands joining an elite club.

"The majority of those living in poor, repressive and unstable countries are not allowed to join the privileged travelling club on the same terms as those from wealthy nations, even if they have the funds to do so," she said in her report on entry clearance in 2004-05.

Additional fees ranging from £3.60 in Bangladesh to £17.85 in Jordan are being charged by private sector firms who process half of all applications for UK Visas, part of the Foreign and Commonwealth Office.

These fees are on top of the standard visa charges, which are £85 for a student on a course lasting more than six months and £50 for a standard six-month visit.

Ms Lindsley's report found that a quarter of a sample of refusals were on the ground of allegations of forgery, with two thirds being refused on this ground in Accra, Ghana. However, 50 per cent of forgery allegations had no evidence to support them.

Ms Lindsley's report, which covers the operation of the visa system in 2004, shows that the overall refusal rate for applications has risen from 6.5 per cent in 2000 to 19 per cent. The refusal rate for students averages 35.4 per cent but is as high as 85.7 per cent in Accra.

Keith Best, chairman of the Immigration Advisory Service, said that the report disclosed a catalogue of failings. "It is clear that there are insufficiencies in entry clearance officers, their training and the way in which we treat applicants coming to Britain. The Government must not think that because these things are out of sight from the British public they are out of mind and can be neglected. The findings are disturbing."

Last week another tape emerged, which apparently showed the murder of a surrendered Serb civilian.

It allegedly showed Croat paramilitaries and Bosnian soldiers harassing and attacking convoys of Serb refugees and shooting one of them who had his hands raised in the air.

Both videos were broadcast by the Serbia B92 television station.

'Burn it all'

Like the previous tape, Tuesday's video was apparently shot during Operation Storm in 1995, when Croatian soldiers recaptured parts of Croatia from ethnic Serbs who had declared independence.

As Serbs fled from the Croat offensive, General Dudkovic appears to order his troops to torch a village - apparently ordering them to "burn it all".

"It is true that I led the operation, but it is not true that war crimes were committed, and even if some had happened, those were individual cases," General Dudakovic told the Fena news agency.

The Serbian government called for the immediate arrest of General Dudakovic and "other war criminals".

"The recordings, which beyond any doubt testify about Dudakovic's misdeeds, represent evidence that must be taken as the basis for immediate action by police and judiciary," it said in a statement.

The republic of Serb Krajina was a self-proclaimed entity in Croatia, lasting from 1991 to 1995, until Operation Storm brought it under Croat control.

The military operation forced the exodus of about 200,000 Serbs who fled into Bosnia and Serbia.

Hundreds of Serb civilians were killed - mostly elderly people who stayed on after their families had left.

In 2001, General Ante Gotovina was indicted by the Hague tribunal for alleged crimes committed by Croatian forces during Operation Storm.

Former Croatian General Ante Gotovina, who led the offensive, is being tried at The Hague in relation to the killing and forced eviction of ethnic Serb civilians.

Eight Sudanese humanitarian workers were killed last month, more than in the previous two years. The crisis is so acute that at least one prominent aid agency has flown in a trauma team to counsel staff.

"There is extreme tension across Darfur," said Suliman Baldo, the Africa programme director for the International Crisis Group, who was in Sudan last week. "The peace deal is on the verge of collapse," he added.

The agreement, signed on May 5, was meant to end the violence that has left more than 180,000 dead and 2 million displaced since the Arab-dominated government began targeting African tribes in February 2003. It now seems clear the deal was deeply, and perhaps fatally, flawed.

Only one of Darfur's rebel groups signed up - a faction of the Sudan Liberation Army (SLA) led by Minnie Minnawi. Though commanding the strongest force, Mr Minnawi, who hails from the minority Zaghawa tribe, had little support on the ground. Most of the displaced in Darfur are Fur, and trust neither Mr Minnawi, who has been appointed as a special adviser to the president, Omar al-Bashir, nor the government.

Reports suggest Mr Minnawi's troops are receiving help from the government and its proxy Janjaweed militia in fighting rival rebel groups, most of which have splintered and formed new alliances since May. Abdel Wahid, who headed the SLA faction and enjoyed widespread support in the camps, appears to have been toppled by a coalition of field commanders.

The new National Redemption Front now appears the strongest and most active rebel movement. Made up of the Justice and Equality Movement, which also shunned the peace deal, and dissident fighters from both SLA factions, it controls much of north Darfur. On Monday it claimed to have shot down a government Antonov aircraft.

"There is much more violence than everyone expected and the situation has quickly become fluid and complicated again," said Eltayeb Hag Ateya, director of the peace research institute at Khartoum University. "We thought Darfur inter-dialogue may work, but it hasn't and it seems we are in trouble now."

The camps are awash with rumour and suspicion. On July 20, three water and sanitation workers were beaten to death in a camp near Zalingei. With banditry and rebel attacks on the increase, effective aid work is becoming near impossible. Tearfund, Care, Relief International and Oxfam have all had staff killed in recent weeks, and Médecins sans Frontières' vehicles have been repeatedly attacked.

"We cannot drive outside most main towns," said Alun McDonald, a spokesman for Oxfam. As soon as we do, our cars get stolen and our staff beaten up."

The government has become increasingly emboldened. Last week, even as the UN secretary general, Kofi Annan, pushed for 18,600 troops to replace the toothless 7,000-strong African Union mission, the government issued several statements rejecting any intervention.

The status quo suits Khartoum, said Mr Baldo. "All along, the government has been very actively promoting ethnic divisions and splintering the rebel groups to try to vindicate its claim that the Darfur crisis was always just a tribal problem," he said. "It's really Machiavellian."

Main rebel groups:

SLA (Minnawi) The only faction to have signed the peace deal. Leader Minnie Minnawi is special adviser to the government

SLA (Wahid) Opposed to the peace deal. Its former leader Abdel Wahid appears to have been toppled by field commanders. Strong support in refugee camps

National Redemption Front Comprises the Justice and Equality Movement, former commanders from both SLA factions, and the Sudan Federal Democratic Alliance. Against the peace deal

G19 Dissident rebels once under Wahid. Against the peace deal and aligned to National Redemption Front. Popular and active in north Darfur

"The records you have requested are records of the investigation and part of the investigatory file in this matter," replied Gary P. Gross, principal deputy for the county counsel's office. That means they must remain sealed, Gross said.

Gibson was arrested early July 28 after he was stopped for driving 87 mph in a 45-mph zone. He was released on his own recognizance later that day.

The 50-year-old actor-director, charged with misdemeanor drunken driving and having an open container of alcohol in his car, is scheduled to be arraigned Sept. 28.

Questions have been raised about the fact that a Sheriff's Department spokesman initially said Gibson had been arrested "without incident" and made no mention of what Gibson himself latter called his "belligerent" and "despicable" behavior.

The arresting deputy's initial written report, which contained Gibson's statements, was also ordered modified and the comments placed in a supplemental report.

No decision has been made on whether to pursue further legal action, the Web site's attorney, Alonzo Wickers IV, said Tuesday.

Harvey Levin, who runs TMZ, said he would wait to see "how the case plays out."

"It could go to trial, and if it does, the tapes would become evidence," he said.

Meanwhile, California's Republican candidate for lieutenant governor, Tom McClintock, said he no longer will use a fundraising letter sent on his behalf by Gibson.

McClintock decided to pull the letter after the incident, his campaign spokesman, Stan Devereaux, said Tuesday.

"Tom saw the news and the situation as it was unfolding with Mel Gibson and made a conscious decision to direct people not to use the letter any further. He was disillusioned by the situation with Mr. Gibson," Devereaux said.