US: President Bush has said the US and its allies have foiled 10 major terrorist plots since September 11th, 2001, including a plan to use hijacked aircraft to attack targets on the east and west coasts in 2002 and 2003.
The president's claim came in a speech that promised to keep US forces in Iraq until the insurgency is defeated and warned that Muslim radicals wanted to create an authoritarian, Islamic empire from Spain to Indonesia.
Police sealed off part of New York's Pennsylvania Station yesterday following a warning from the city's mayor, Michael Bloomberg, that terrorists were planning to attack the subway system with a bomb concealed in a baby's push chair.
Homeland Security officials cast doubt on the mayor's claim but police and National Guard soldiers were out in force on the subway yesterday.
The White House said the foiled plots included three within the US - a plan to blow up apartment buildings, perhaps with a "dirty bomb", and plans to use commercial aircraft to attack targets on the east and west coasts.
Mr Bush used his speech to the National Endowment for Democracy to turn the political spotlight back on the war against terrorism and to reject calls for an early exit from Iraq.
He said that groups such as al-Qaeda wanted to end American and western influence in the broader Middle East as a prelude to gaining control of one country and later establishing an Islamist empire.
"The terrorists regard Iraq as the central front in their war against humanity. And we must recognise Iraq as the central front in our war on terror," he said. The militants hoped that controlling Iraq would help to rally the Muslim masses, enabling them to overthrow all moderate governments in the region.
"With greater economic and military and political power, the terrorists would be able to advance their stated agenda: to develop weapons of mass destruction, to destroy Israel, to intimidate Europe, to assault the American people, and to blackmail our government into isolation."
Rejecting claims that the US presence in Iraq was fuelling Islamic radicalism, Mr Bush said that retreat or appeasement would make matters worse.
"Against such an enemy, there is only one effective response: we will never back down, never give in, and never accept anything less than complete victory," he said.
The president compared Islamic radicalism to communism, describing it as "elitist, led by a self-appointed vanguard" that is indifferent to the suffering of its own people.
"Like the ideology of communism, our new enemy pursues totalitarian aims. Its leaders pretend to be an aggrieved party, representing the powerless against imperial enemies. In truth, they have endless ambitions of imperial domination, and they wish to make everyone powerless except themselves," he said.
Meanwhile, the Pentagon claimed that a letter written by al-Qaeda's second-in-command, Ayman al-Zawahri, points to a split within the network over tactics used in Iraq.
Pentagon spokesman Bryan Whitman said that the letter, addressed to Abu Musab al-Zarqawi, the leading al-Qaeda figure in Iraq, warns that some terrorist tactics risk alienating the Muslim masses.
"Zawahri does say that the insurgents in Iraq should avoid using tactics such as bombing of mosques and slaughtering of hostages in order not to alienate the masses. In this letter, he talks about believing that the eventual governance of Iraq must include the Muslim masses, and that they are at risk of alienating those," he said.
Mr Whitman said the letter reinforced the president's claim that al-Qaeda wanted to create an Islamic empire centred on Iraq but it also suggested that the movement had been badly weakened by US and allied action.
"Zawahri says that they've lost many of their key leaders and that they've virtually resigned themselves to defeat in Afghanistan, that their lines of communication and funding have been severely disrupted," he said.