President Bush has given the CIA an explicit go-ahead to carry out covert missions to assassinate Osama bin Laden and his supporters around the world, effectively lifting a 25-year ban on such activities.
The US defense secretary, Donald Rumsfeld, confirmed reports of such a move yesterday by telling CNN that the US would be acting in self-defence in carrying out such missions.
The Washington Post reported yesterday that Mr Bush has decided that executive orders banning assassinations since a series of botched attempts in the 1960s and 1970s allow him to single out a named terrorist or terrorists for death by covert action.
Mr Rumsfeld said: "It is not possible to defend yourself against terrorists at every single location in the world and at every single moment.
"The only way to deal with terrorists is to take the battle to them and find them and root them out and that's self-defence. We're going after these people and their organizations and capabilities and to stop them killing Americans."
The US president, according to senior government officials quoted by the Post, signed an order last month known as an intelligence "finding", which broadens the list of potential targets beyond Bin Laden and his immediate circle of some 15 operational planners - and beyond Afghanistan.
The CIA, pilloried in some quarters along with the FBI last month for its fatal failure to detect the movements and plans of the al-Qaida terrorist network, is said to be willing and able to "take the lives of terrorists designated by the president".
Mr Bush has apparently circumvented the legal constraints on clandestine killing missions imposed since the Church committee found in 1975 that plots against five foreign leaders under presidents Eisenhower, Kennedy and Nixon had been organized in terms "so ambiguous that it is difficult to be certain at what levels assassination activity was known and authorized".
The new presidential order, drawing on one signed by President Clinton against al-Qaida three years ago, apparently overcomes such problems by making plain that responsibility and accountability rest with the president and his senior colleagues.
"I would want the president's guidance to be as clear as it could be, including the names of individuals. You have got to have the political levels behind you so the intelligence officers are not left hanging," the recently retired CIA deputy director, John Gannon, told the Post.
But history suggests that covert assassinations remain fraught with danger and carry a high risk of failure.
Jeffrey Richelson, an intelligence historian and author of a new book on the CIA, said of pre-1975 efforts: "They never succeeded in killing anyone. They were the gang that couldn't shoot straight."
Agents carried out numerous inept missions to kill Fidel Castro, using among other botched devices bacteria in his favorite type of cigar, an exploding seashell, and a poisoned wet suit. Other botched missions were undertaken in central America, the Congo and Iraq, though Mr Richelson has said the CIA did significantly aid the assassins of Che Guevara, and, indirectly, the overthrow of Chile's Salvador Allende in 1973.
Yesterday's report suggested that President Bush's order could extend well beyond the al-Qaida network concentrated around Bin Laden and the FBI's 22 "most-wanted" terrorists, with the CIA debating how many of the 35 or more countries identified as places where the terrorist network is active could figure on the list.
Andrew Card, White House chief of staff, said yesterday on NBC's Meet the Press: "It could take years but we are going to do everything we can to rout the terrorists in Afghanistan and then get them all around the world."
Financiers of the al-Qaida - "the Gucci guys, the guys who write the checks", according to one unnamed CIA official - could also be targets but the report said it was unclear whether Mr Bush had "signed orders that would amount to individual death warrants".
© Guardian Newspapers Limited 2001