The United States and its allies have thwarted at least 10 serious al Qaeda terrorist plots since Sept. 11, 2001, including never-before-disclosed plans to use hijacked commercial airliners to attack the East and West coasts in 2002 and 2003, President Bush and his aides said.

The reported plots aimed to strike a wide variety of targets, including the Library Tower in Los Angeles, ships in international waters and a tourist site overseas, the White House said. Three of the 10 were directed at U.S. soil, officials said. The government, they added, also stopped five additional al Qaeda efforts to case possible targets or infiltrate operatives into the country.

Most of the plots were previously reported in some form, while a few were revealed for the first time Thursday. The White House had never before placed a number on or compiled a public list of the foiled attempts to follow up the Sept. 11 attacks, but it offered only scant information beyond the location and general date of each reported plot.

Bush cited the disrupted plots in a speech intended to shore up sagging public support for the war in Iraq and to address more extensively than ever before the philosophical framework undergirding Islamic extremism. The radical movement, he said, goes beyond "isolated acts of madness," with the goal to "establish a radical Islamic empire that spans from Spain to Indonesia."

Bush singled out Syria and Iran for condemnation, saying they have "a long history of collaboration with terrorists, and they deserve no patience from the victims of terror." He rebuffed calls to withdraw from Iraq and dismissed as a "dangerous illusion" the idea that pulling out would make the United States safer. And he rejected the argument that the Iraq war has fostered terrorism.

-- Peter Baker

and Susan B. Glasser

In a speech Thursday, President Bush dismissed as a "dangerous illusion" the idea that pulling out from Iraq would make the United States safer.