AFTER 13 MONTHS of battling a branch of the al Qaeda movement, Saudi Arabia's government has all but declared victory. Authorities say they have wiped out the leadership of all five of the terrorist movement's cells that were known to exist a year ago; the last breakthrough came 10 days ago with the slaying of four militants responsible for the beheading of American Paul M. Johnson Jr. Al Qaeda's Saudi organization, officials say, is in shambles, which is why ruling Crown Prince Abdullah has given its surviving members one month to surrender in exchange for amnesty. This turn of events -- if that is what it is -- can only be welcomed by Arab and Western governments, which just weeks ago watched with alarm as a wave of terrorism killed scores of Saudis and Westerners. Yet the note of triumphalism now heard from Riyadh seems dangerously premature.

The Saudi royal family may have bought itself some respite with the police work -- including massive dragnets in major cities -- that led to the killing or capture of key militants. But hundreds of al Qaeda adherents remain at large in Osama bin Laden's homeland and will probably form new cells. Saudi authorities are moving slowly, if it at all, to address the roots of the insurgency. Officials point to the extremist clerics who have been silenced or forced to recant, and the steps that have been taken to cut off the terrorists' financing. But Western observers, including a recent task force of the Council on Foreign Relations, say the government has yet to take on charities suspected of bankrolling extremism domestically and abroad.

More fundamentally, the Saudi rulers have yet to acknowledge the ways in which Islamic radicals have been bred by the Saudi-sponsored Wahhabi strain of Islam and the state-financed religious establishment. Al Qaeda is frequently described by senior officials as a foreign import, brought back from Afghanistan by Saudis radicalized there. Crown Prince Abdullah himself blamed the violence on "Zionists" in one speech last month. Rather than tackle the hidebound religious establishment or promote alternatives to the strict Wahhabi creed, the government has rounded up and jailed reformers who call for religious and political liberalization.

This is a familiar response from the Saudi regime, which was founded on its alliance with Wahhabi clerics and traditionally has responded to extremist challenges by crushing rebel leaders while appeasing and co-opting their followers. But a recent public opinion poll, conducted by an independent Saudi team, showed wide support for a change in policy. Large majorities favored political and social reform; twice as many supported greater rights for women as said they liked the rhetoric of Osama bin Laden.

The United States, too, can no longer afford to support the Saudi status quo. President Bush has acknowledged as much; in a speech in Istanbul on Tuesday, he again denounced "stability at the price of liberty" in the Middle East and warned that "any nation that compromises with violent extremists only emboldens them." His administration has an opportunity to act on that rhetoric. Mr. Bush should press the Saudi leadership to follow up on its recent success against al Qaeda by introducing the kind of change that Saudi citizens -- as opposed to Wahhabi clerics -- want. The first step is straightforward: Release the advocates of peaceful reform who remain in jail.