Al Qaeda's Summer Plans seems innocent enough. The Abu Dhabi-based Web site offers bulletin boards where Arabic speakers can advertise for wives and exchange messages about sports, politics and the true meaning of jihad. Since the 9-11 attacks, however, the CIA and FBI have closely monitored as a kind of terrorist early- warning system. The reason: on Sept. 9, 2001, a message appeared on the Alsaha Web site proclaiming that, in the next two days, a "big surprise" was coming from the Saudi Arabian region of Asir, the remote, mountainous province that produced most of the 19 hijackers who struck on September 11. So last week, NEWSWEEK has learned, the U.S. intelligence community grew more than a little alarmed when it discovered another cryptic posting on "Oh brothers, further attacks are to come in the next 48 hours," it read. "All good Muslims in New York, Boston and other cities on the seacoast should leave." Was this a starting gun to sleeper cells to spring into action? Another oracle that chaos was about to erupt in America's crowded Northeast corridor? The counterterror analysts were unsure. The FBI and CIA had no other direct warnings of an attack, and analysts could not rule out the possibility that the terrorists were planting disinformation to stir panic. Yet the terrorist "chatter" level was on the rise again. Electronic intercepts from tapped phones and spy satellites suggested that Al Qaeda operatives around the world were planning something.

Every morning, President George W. Bush is shown a threat "matrix," an elaborate distillation of the various signals--some faint and far-off, some clanging like a fire bell in the night--emanating from an elusive but maddeningly resilient enemy. Last Wednesday the gong was loudly sounded on Arab TV by no less a figure than Ayman Al-Zawahiri, the creepy Egyptian doctor who has long served as Osama bin Laden's No. 2 and is widely regarded as the brains of Al Qaeda. Al-Zawahiri is supposed to be hiding in a cave, but he sounded as ominous as ever. "The Crusaders [Americans] and the Jews only understand the language of force, and they only understand the return of coffins and destroyed interests and burned towers and destroyed economy," the doctor intoned on a scratchy audiotape to all "dear Muslims." "Your brothers the mujahedin are following your enemy and waiting to ambush them... the coming days will carry good news that will heal your heart."

What news? The counterterror analysts at the CIA and FBI were not taking any chances. They warned that the war on terror was entering a new and more dangerous phase, "an orchestrated Spring/Summer worldwide offensive," as one internal document put it. "It is likely that an attempted terror attack against the US Homeland... could occur in the next 30-90 days," predicted the document, described to NEWSWEEK by U.S. intelligence sources. Information from detainees suggested the targets could include subway systems in American cities. (According to a top law- enforcement official, several Qaeda operatives in the United States have begun cooperating with U.S. intelligence, exposing ongoing plots.) The spooks were particularly worried about a Canadian connection. One of the leaders of the terror attacks in Saudi Arabia last week, Abdul Rahman Jabarrah, has a Canadian passport. A British intelligence document obtained by NEWSWEEK says that the terror cell that plotted the foiled bombing attack from Canada on Los Angeles airport during the Millennium celebrations is still active. In some of the chatter picked up by American eavesdroppers, Al Qaeda sympathizers complained that more Muslims than Westerners had died in the recent terror attacks in Saudi Arabia and Morocco. According to one national---security official, the response from Al Qaeda leaders was, in effect: "Don't worry. We'll correct that in the future."

That was enough for the policymakers and politicians. The Homeland Security Council--the senior, cabinet-level committee that regularly reviews the nation's readiness--decided to ratchet up the official terror threat to Code Orange, "high risk." A senior law-enforcement official told NEWSWEEK: "This looks eerily similar to the way it looked right before September 11."

Here we go again. This is the fourth time in the past year that the Bush administration has taken the nation from Code Yellow ("elevated") to Code Orange. The nation (especially the part that lives in ground-zero cities like New York and Washington) was thoroughly shaken last February. Suggestions to buy duct tape made the mothers of small children picture themselves pathetically trying to seal their windows and doors against clouds of poison gas. Then came heartening news: arrests of top terror thugs, like Al Qaeda's alleged operations chief, Khalid Shaikh Mohammed, who was surprised, looking paunchy and sleepy, in his Pakistani hideout in early March. The war in Iraq came and went without a retaliatory strike. The president, bestriding a carrier deck like Tom Cruise, declared that Al Qaeda was "on the run."

Yet now the terrorists seem to be rising again from their graves, like ghouls in a horror show. Americans could not be blamed for weariness, doubt and a touch of cynicism. Is Code Orange little more than a bureaucratic device that allows nervous policymakers to cover themselves, just in case something really does go wrong? Could it be that the Bush administration wants to remind voters from time to time that the terrorists are still out there--and that it takes a strong commander in chief to stand tall against the threat?

The mood swings are misleading. In truth, the United States is engaged in a quiet, dirty war that has gone on, and will go on, for years. The weapons are technology (spy satellites, eavesdropping devices, code-breaking computers), vigilance and careful coordination between rival government agencies (a big problem prior to 9-11), and buckets of cash, spread around to win friends in foreign intelligence services (the intelligence community's secret, or "black," budget has reportedly increased by half in the past two years). Progress is necessarily slow. Al Qaeda morphs and mutates "like a virus," says Richard Haass, outgoing Director of Policy Planning at the State Department . "It's just like fighting a disease. You rarely have permanent or complete victories."

In a suite of rooms filled with harried- looking analysts staring at computer screens deep inside CIA headquarters in Langley, Va., the newly created Terrorist Threat Integration Center tries to connect the dots. "It's an art and a science," says a senior intelligence official. Sometimes, more art than science is involved. "There are just lots of pieces. It really is a puzzle," acknowledges the official. The analysts in the TTIC--drawn from the FBI, CIA, State and Defense, and the alphabet soup of government agencies lumped into the Department of Homeland Security--are often working "on the margins," he says. Al Qaeda has been "knocked back on its heels" since 9-11, says the official, who describes the terror network as "a wounded animal."

And like a wounded animal, dangerous. The analysts in the TTIC were struck by Al Qaeda's wholesale slaughter of Muslims in the attacks in Saudi Arabia. Normally, Saudi Arabia is a recruiting and funding center for Al Qaeda, not a target. The impact of the attacks, which killed 34 people (eight Americans), was to warm up the sometimes chilly ties between the Saudi regime and Washington. One top official in a neighboring Arab nation described a debate that had been going on in Saudi Arabia between the hard-liners, who wanted to crack down on Al Qaeda, and the soft-liners, who wanted to deal with the fundamentalists by embracing them. "After what was done in Riyadh, the hardliners have won," said this official. "Everybody is united." The Saudi Interior minister, Prince Nayef, who once dismissed the existence of Al Qaeda in the kingdom and blamed the 9-11 attacks on "the Jews," is now working more closely with the CIA and FBI. They are trying to root out the five or so Qaeda cells (each numbering 12 to 20 operatives) believed to be hiding inside Saudi Arabia.

Al Qaeda's willingness to antagonize the Saudi regime suggests a level of desperation. "They've lost a lot of key people. They have to show they are resilient," a senior intelligence official told NEWSWEEK. What better way than to attack the American homeland? The desire and intention appears to be there. Less certain is whether Al Qaeda can pull off such an attack, at least on a scale resembling the September 11 suicide hijackings.

Since the Iraq war, Al Qaeda has been able to recruit angry young Arab males determined to strike at the "Crusaders." Intelligence officials caution that they have no evidence that Al Qaeda operatives have made off with nuclear material or chem-bioweapons from Saddam's mysterious--and still missing--WMD arsenal. Not all the new recruits are geniuses. In the Morocco attacks, British intelligence officials tell NEWSWEEK, some of the bombers appear to have struck the wrong targets. The bombers who hit the Spanish cafe in Casablanca "got lost," say these sources. Last week three Moroccans checked in for a flight out of the Jidda airport in Saudi Arabia. Saudi officials identified one on a terrorist watch list. The other two were questioned: are you both with him? One said no. The other said yes. The Saudis arrested all three and discovered them carrying knives--possible weapons for a hijacking. Less encouraging, in the Morocco attack an unsophisticated band succeeded in using homemade explosives to carry out a coordinated attack in which 12 of 14 bombers completed their suicide mission.

Al Qaeda has always been more of a pirate federation than a Stalinist top-down organization. "It's not IBM," says a U.S. counterterror analyst. While financed by Al Qaeda, the Moroccan terrorists were an offshoot group. Some franchises are stronger and smarter than others. Intelligence officials are trying to gauge the reach and power of a cleric who has spent most of his time in London, or "Londistan," as the Feds call the area around the Finsbury Park mosque. A London imam, Abu Qatada, appears to European authorities to have had a role, possibly more inspirational than organizational, in any number of planned and accomplished catastrophes. According to a British dossier obtained by NEWSWEEK, as far back as the mid-'90s, Abu Qatada issued a fatwa for the slaughter of women and children in Algeria by a radical organization called the Armed Islamic Group (GIA). Jordanian authorities implicated Abu Qatada in the planned (but thwarted) Millennium attacks on American tourists. The imam was said by the French to have provided "spiritual advice" for terrorist plots in Strasbourg and Paris in 2000 and 2001, and 18 tapes of his sermons were found in the Hamburg apartment of Muhammad Atta, the lead hijacker on 9-11.

The case of Abu Qatada illustrated the difficulty of shutting down a Qaeda branch. The imam has been held without trial in a high-security British prison since last October. (He denies being a terrorist and is appealing his detention.) Yet British authorities believe that he somehow delivered instructions to followers in Britain and elsewhere around Europe to launch a series of terror attacks using homemade batches of ricin, a lethal poison. Dozens of plotters were arrested in Britain, France and Spain, and U.S. intelligence believes that other suspected plotters are still on the loose.

U.S. intelligence believes that some senior Qaeda leaders are holed up in Iran. Scores of Qaeda fighters fled there after U.S. forces toppled the Taliban in Afghanistan. The question--a source of considerable debate in the intelligence community--is whether Iran is a safe haven or a jail cell for Al Qaeda. Some intelligence officials, principally at the CIA, believe that Saif Al-Adel, an Egyptian who is reputedly Osama bin Laden's intelligence and security chief (No. 3 in the Qaeda pecking order), is now in custody in Iran. But other intelligence analysts, primarily Pentagon hawks, believe that Al-Adel--along with bin Laden's son Saad, and Abu Musab al-Zarqawi, a one-legged Jordanian militant with alleged ties to the former Saddam Hussein regime--are being secretly supported in Iran by Islamic extremists in the Iranian clerical establishment.

The more urgent question to most Americans is whether Al Qaeda is operating inside the United States. The answer is yes. "The only thing we can say with certainty is that they're here," says a top law- enforcement official. Al Qaeda has been patiently working on ways to get inside America in the new age of heightened security. Al Qaeda has long studied American vulnerabilities. After 9-11, American soldiers and spooks rooting through the caves of Afghanistan found technical reports by the U.S. General Accounting Office, detailing weak links in the U.S. infrastructure. Lately, Al Qaeda has been working on the problem of sneaking spies and suicide bombers across the borders. The terrorists are looking for new pools of potential assets--Canadians, women and African- Americans--and Arabs with "clean" passports, i.e., not on any watch list.

With a million legal immigrants and 42 million visitors to the United States each year, weeding out terrorist operatives is a daunting task. The FBI and CIA are worried about suspected terrorists like Abdul Rahman Jabarrah. A protege of Khalid Shaikh Mohammed's, the operations chief arrested in February, Jabarrah is alleged to have been a key figure in the Saudi bombing attack. His younger brother Mohammad, captured in Oman last year, gave interrogators a chilling description of how the Jabarrah brothers became Qaeda --hit men. Schooled in Canada (where his father was a successful businessman) and trained in the Afghan terror camps, Mohammed Jabarrah says he became an acolyte of bin Laden's. "The Source [Jabarrah] explained to UBL [bin Laden] that he spoke English very well and had lived in Canada for six or seven years, so he had a 'clean' Canadian passport," reads an intelligence document obtained by NEWSWEEK. Jabarrah told his interrogators some Qaeda code: "Market" meant Malaysia. "Hotel" was the Philippines. "White meat" was an American.

The Feds have identified a few Qaeda soldiers already in the United States. Intelligence sources tell NEWSWEEK that during his interrogation, Khalid Shaikh Mohammed fingered an Ohio truckdriver. In a major breakthrough, the Feds picked up the truckdriver, who began to cooperate. According to law-enforcement sources, the truck- driver was involved in plots to bring down a bridge and blow up an airliner. The truckdriver was asked by his Qaeda masters to obtain the proper tools for loosening the bolts on a suspension bridge. As for the airliner, the truckdriver said that cargo trucks could easily drive underneath passenger jets without arousing suspicion.

Working together in unprecedented harmony, the FBI and CIA have a much better handle on the terrorist threat they had pre-September 11. The many captured Qaeda leaders have been a treasure-trove of information. Under interrogation, the prisoners have spilled the identities of confederates and the details of many plots. The CIA and FBI do not always know whom or what to believe--the terrorists often spew lies along with the truth. But the intelligence services have been able to build up vast databases to cross-check leads.

U.S. intelligence has had plenty of help from abroad. Millions of dollars spread across the Arab world have encouraged the cooperation of intelligence services as well as potential informants. Even while the governments of Germany and France were feuding with the United States at the United Nations last fall, the French and German security services were continuing to cooperate with the CIA and FBI, in part because the Qaeda threat is every bit as real in Europe as it is in the United States.

It is not always possible to separate the good guys from the bad guys in the war on terror. Al Qaeda has sympathizers and outright spies planted in many places. In Yemen, a number of top Qaeda operatives, including several involved in the 2000 bombing of the USS Cole, somehow managed to escape from jail on April 11. In Saudi Arabia, a bungled police raid allowed 19 Qaeda suspects to get away--to stage a bombing a week later. Had they been tipped off? The war on terror will never be neat or clear-cut. Nor will it be short. "These people have a different sense of time," says a senior intelligence official. "They hark back to the Crusades. For them, the jihad is never-ending."