ASHINGTON — In past weeks Al Qaeda has relaunched itself, a rebranding that presages a second phase in its war against the West. The clearest evidence for this shift is in three audiotapes that Al Qaeda has released since the beginning of October from its top leaders, Osama bin Laden and Ayman al Zawahiri.

Most analysts both inside and outside the government believe those tapes to be authentic. On them, the two Qaeda leaders call for a wider war against not only the United States but the West in general, with a wider range of targets. Al Qaeda has chosen war against all "the Crusaders," not just Americans. The front can be anywhere.

This shift was precipitated by Al Qaeda's loss of its headquarters in Afghanistan. Deprived of a physical base, Al Qaeda has morphed into something at once less centralized, more widely spread and more virtual than its previous incarnation.

Earlier this week, Al Jazeera television released an audiotape that is almost certainly from Mr. bin Laden. Apart from the fact that this seems to confirm that the world's most wanted man is indeed alive, the tape is also significant because Mr. bin Laden threatens by name not only the United States but Britain, France, Germany, Italy, Canada and Australia.

Those threats should be taken at face value. Mr. bin Laden's statements have been a reliable guide to the subsequent actions of Al Qaeda, and in the past he has presaged his most spectacular attacks with some public announcement.

In May 1998, Mr. bin Laden told journalists he made no distinction between American military and civilian targets. Three months later Al Qaeda blew up two American embassies in Africa almost simultaneously. A few months before the October 2000 bombing of the destroyer Cole in Yemen, Mr. bin Laden released a videotape threatening the United States in which he was wearing a distinctive Yemeni dagger.

The new wave of attacks is likely to be on economic targets. Mr. bin Laden, who studied economics and public administration at university, reveled in the economic impact of the attacks on Manhattan. In a videotape aired on Al Jazeera late in 2001, he gloated that the combined effect of the drop in the value of the stock market, physical damage to New York and the loss of jobs in a variety of industries cost the American economy "no less than one trillion dollars."

Al Qaeda is a group that learns from experience, so it should not have been surprising that early last month, around the anniversary of the start of the American war against the Taliban, an audiotape purported to be from Mr. bin Laden was released saying, "The youths of God are preparing for you things that would fill your hearts with terror and target your economic lifeline."

That was followed by a statement, probably recorded in July, from Mr. al Zawahiri, Al Qaeda's cerebral strategist, who called for "the destruction of the American economy." On Oct. 6 a boat loaded with explosives disabled an oil tanker off the coast of Yemen; days later a bomb ripped through a tourist disco on Bali. Tourism and the oil business are, needless to say, vital to the global economy.

By focusing on economic interests, Al Qaeda has also managed to reach beyond American targets. In April a truck bomb outside an historic Tunisian synagogue killed a group of German tourists. In May, Al Qaeda killed 11 French defense contractors staying at a Sheraton hotel in Karachi, Pakistan. The oil tanker attacked in Yemen was also French and most of the more than 180 victims of the blast in Bali were Australian. On the new audiotape Mr. bin Laden praises these attacks as the work of "pious Muslims."

These trends underline the fact that the war of the terrorists has entered a new phase — as must the war on terrorism. After the attacks on New York and Washington, Al Qaeda was subjected to a military campaign intended to extirpate the group.

However, Al Qaeda had only a partial return address in Afghanistan. Now it lives on as an organization as much virtual as it is real, releasing videotapes and audiotapes while its members communicate with one another from untraceable Internet cafes. Truly Al Qaeda 2.0.

Peter L. Bergen is a fellow of the New America Foundation and the author of "Holy War, Inc.: Inside the Secret World of Osama bin Laden."