The seventh anniversary of the 9/11 atrocities exposed fresh cracks in America's War on Terror today after it emerged that President Bush secretly authorised US special forces to conduct ground operations inside Pakistan without Islamabad's approval.
The news, in a report from The New York Times, was corroborated by Admiral Michael Mullen, chairman of the Joint Chiefs of Staff, who has confirmed that he had ordered a new strategy for Afghanistan focusing on both sides of its border with Pakistan, including those tribal areas that have become a virtual safe haven for al-Qaeda.
"I'm not convinced we're winning it in Afghanistan. I am convinced we can," Admiral Mullen told a congressional committee in Washington.
The new strategy was welcomed by President Karzai of Afghanistan, who said that he had been pushing for such a shift in focus for years to help tackle the Taleban insurgency at its root.
But Mr Karzai warned that he opposed the long-term presence of foreign troops in Afghanistan, where there are some 71,000 troops under either Nato or direct US command.
"It is natural that the international community cannot stay here forever and it is not good for us that they stay," he said.
Citing senior officials, The New York Times reported that Mr Bush secretly approved the new incursion orders in July. The report follows a wave of missile strikes targeting militants in Pakistan that have been attributed to US-led coalition forces or CIA drones based in Afghanistan.
Those attacks have caused many civilian casualties, angering many Pakistanis and straining relations with Pakistan's civil and military leadership.
Last week, Pakistan for the first time accused Afghanistan-based troops of carrying out a direct attack on its territory, a raid in the South Waziristan tribal zone that left 15 people dead.
In a statement today, General Ashfaq Kayani, the Pakistani army chief. strongly criticised the raids and insisted there was no deal allowing foreign troops to conduct operations on Pakistani soil. "The sovereignty and territorial integrity of the country will be defended at all cost," he added.
Meanwhile, John McCain and Barack Obama, the Republican and Democratic rivals for the White House, called a truce in their increasingly bitter contest as a mark of respect for those who died in America's worst terrorist attacks. With campaign advertising suspended, the two men were to make a joint appearance at Ground Zero, the site of the former World Trade Center in Manhattan.
"There will be no speeches," Democrat Obama's spokeswoman Linda Douglass said."This is going to be a moment when politics are set aside."
Heavy security was in place well ahead, with streets near Ground Zero closed and buses re-routed before ceremonies starting at 8.40am (1240 GMT). Two separate minutes of silence were to mark the moments when the two hijacked airliners struck on September 11, 2001, destroying each of the Twin Towers and killing some 3,000 people -- at 8:46 am and at 9:03 am.
Ceremonies included additional minutes of silence commemorating the collapse of each tower, as well as the traditional reading out of all victims' names.
Over the last week the White House contest has degenerated into name-calling, climaxing with the row over Mr Obama's branding of the Republican campaign of Mr McCain and running mate Sarah Palin as "lipstick on a pig".
But Mr Obama set the tone for the Ground Zero event, saying last night that that 9/11 showed"that here in America, we all have a stake in each other; I am my brother's keeper, I am my sister's keeper - and we rise and fall as one nation".