Al Qaeda's second-in-command, Ayman Zawahiri, said U.S. defeat in Iraq and Afghanistan "has become just a question of time," in a videotape broadcast yesterday on the approach of the third anniversary of the terrorist network's attacks on the World Trade Center and the Pentagon.

"The Americans in both countries are between two fires; if they continue, they will bleed until death, and if they withdraw, they will lose everything," the al Qaeda leader said in a tape shown over the al-Jazeera television network, according to a translation by a U.S. government agency.

Yesterday marked the third year that Osama bin Laden's terrorist organization has released a tape around Sept. 11. In the first two videotapes, bin Laden took part with Zawahiri; this time only Zawahiri appeared, wearing a white turban.

While U.S. intelligence analysts are reviewing the tape, there was little doubt yesterday about its authenticity, said a senior administration official. Other specialists are studying the possible reasons for bin Laden's failure to appear in either the video or audio portions, the official said, adding that making a tape may have been too risky since it "would raise his profile, even temporarily."

Bin Laden has not appeared in a video whose taping date could be accurately established since one broadcast on Dec. 27, 2001, the official said. In yesterday's tape, references by Zawahiri to the Iraqi interim government in Baghdad and the situation in the Darfur region of Sudan indicate it was done fairly recently, officials said.

In 2002, on the eve of the first anniversary of the attacks, an audiotape included bin Laden praising the terrorists who took part in the attacks. Last year, the videotape showed bin Laden and Zawahiri walking in a mountainous area in undated footage. Meanwhile, on the audio track that accompanied the video, bin Laden again praised those who carried out the 2001 attacks while Zawahiri called on "our brother mujaheddin in Iraq" to continue attacking U.S.-led forces there.

Although much of what Zawahiri said in yesterday's tape involved Afghanistan, he said that in Iraq, the mujaheddin "have turned America's plan upside down after the interim government's weakness became clear."

As for Afghanistan, where scheduled elections in October may be in doubt because of fighting, Zawahiri said areas in the east and south "have now fully become an open arena for the mujaheddin." He said the Kabul government supporters "have been confined to the province's capitals" and that the Americans "are staying now in their trenches and refuse to come out to meet with the mujaheddin."

A spokesman for the U.S. Central Command, Maj. Matthew McLaughlin, said by e-mail that his organization, which directs forces in Afghanistan, "is not going to engage in a battle of press releases/statements with terrorists. Centcom remains committed to its mission in Afghanistan."