Deep inside the Metropolitan Correction Center in Manhattan, a taxi driver from Florida named Ihab M. Ali sits in the same high-security cellblock as five men accused of plotting the twin truck bombings that shattered two U.S. embassies in East Africa last August.

Ali hasn't been charged in the case, but prosecutors think he may know something about it. And they're squeezing him. Since they offered him immunity from prosecution and he still refused to testify to a grand jury, he is charged with contempt of court and held under unusually tight conditions, with just one hour a day outside his cell.

Such is the hardball that authorities are playing as they build a massive federal indictment against Saudi millionaire Osama bin Laden and 16 co-defendants for conspiring to bomb the embassies and "to murder U.S. nationals anywhere in the world."

The indictment describes bin Laden as the leader, or "emir," of al Qaeda, a "global terrorist organization" with tentacles that allegedly reach from his hideout in the mountains of Afghanistan to followers in Texas, Florida and New York.

But the portrait of al Qaeda -- Arabic for "the Base" -- that emerges from hundreds of pages of court filings looks less like a tight-knit group under one man's command than a disjointed, shadowy confederation of extremists from all over the Islamic world.

The bombings of the U.S. embassies in Kenya and Tanzania killed 224 people, including 12 Americans, on Aug. 7, 1998. As the first anniversary of the attack approaches, prosecutors are still months away from being ready for trial. And, from court records as well as interviews with government officials and terrorism experts, it remains unclear whether al Qaeda has managed to assemble a powerful and dangerous network inside the United States or merely a sprinkling of sympathizers whose links to one another, and to bin Laden, are often tenuous.

Five of the defendants -- including a tire store manager from Texas and a former U.S. Army sergeant -- are now in custody in New York. Three others are being held in London. And nine -- including bin Laden -- remain at large.

Many of the suspects volunteered to fight alongside the Afghan mujaheddin against the Soviet Union in the 1980s and now look to bin Laden, a legendary figure among Arab veterans of the Afghan war, for spiritual guidance in the struggle against the next great infidel, America.

"To imply something too organized, too hierarchical, misses the reality," said Brian Jenkins, a terrorism expert at the Rand Corp. "We're obliged to talk about universes of like-minded fanatics -- nothing that appears like a wiring diagram Western bureaucrats are familiar with."

The government's indictment describes this global organization in terms that sound like the Mafia, with members who "made bayat" -- swore allegiance -- to bin Laden and signed written contracts enforceable by a Judicial Committee of al Qaeda leaders.

But for all its claims about a worldwide conspiracy to murder Americans, the government's case is, at present, largely circumstantial. The indictment never explains how bin Laden runs al Qaeda or how he may have masterminded the embassy bombings. Only eight of the 17 suspects are alleged to have been in Kenya and Tanzania around the time the embassies were bombed.

Investigators clearly are being guided by intelligence that is not reflected in the indictments. But much of that information -- including electronic intercepts of telephone calls and interrogations of suspects by foreign intelligence agencies -- also may not be usable in court, either because of the way it was obtained or because making it public would reveal U.S. intelligence sources and methods.

The voluminous evidence compiled by the FBI traces a web of relationships that allegedly link bin Laden and his followers to a series of "fatwas," or religious rulings, that call for killing Americans and to a string of terrorist acts in which Americans have, indeed, been killed. As they go forward, investigators hope to turn that circumstantial case into a more definitive one and to find all the members of al Qaeda's network in America, which they do not think they have yet done.

"The numbers are murky, as to the size of this problem," said Robert M. Blitzer, former chief of the FBI's domestic terrorism section. "But it is a problem -- and it is going to continue to be a problem for some time to come."

Jersey City Businessman

Mustafa Elnore, a small businessman from Jersey City, N.J., is the latest Islamic activist picked up by federal prosecutors in Manhattan. He was arrested last month and charged with lying about his relationships to a number of alleged and convicted terrorists, beginning with El Sayyid Nosair, who is serving a life sentence for plotting to bomb the World Trade Center and other New York City landmarks in 1993.

Court papers filed against Elnore list no direct connection to the embassy bombings case. But federal prosecutors think he may be a link between bin Laden and Sheik Omar Abdel Rahman, a blind Egyptian cleric who is also serving a life sentence for the New York landmarks case.

The tenuous chain goes as follows: Elnore has been charged with lying about his relationship to Nosair. Nosair was convicted alongside Rahman. Rahman was a key figure at the Alkifah Refugee Center in Brooklyn. And the Alkifah center, according to prosecutors, was not only a hub for the plotters of the World Trade Center bombing but also helped spawn al Qaeda in the late 1980s.

A decade later, the number of al Qaeda operatives in the United States now willing to engage in actual terrorist acts is probably small, according to Blitzer, who retired in November as the FBI's top domestic terrorism official.

But networks of supporters may be far larger. "With a lot of these guys, there are the ones who will do things -- bombers and shooters -- and others who will support them," Blitzer said. "And that's where the numbers get bigger."

In the Elnore case, there's also this indirect link to the alleged embassy bombings conspiracy: One of the individuals Elnore is charged with lying about to the grand jury is Wadih Hage, the tire store manager from Texas.

Texas Tire Store Manager

Hage came to the United States in 1978 to study city planning at Southwestern Louisiana University. He married an American, fathered seven children, went off to help the Afghan mujaheddin fight the Soviet Union, and ended up working as bin Laden's personal secretary in Sudan in the early 1990s.

The indictment does not describe any direct role played by Hage in the bombing of the embassies in Kenya and Tanzania. But it does allege that he was at the heart of al Qaeda and traveled around the world on his U.S. passport to meet with operatives, manage communications, move money for bin Laden and even scour the globe for chemical weapons.

By 1994, the indictment says, Hage had moved to Kenya and helped establish an al Qaeda cell in Nairobi -- the same unit that allegedly plotted last summer's embassy bombing there.

Hage finally returned home to the United States in 1997 and resumed the life of a working stiff, earning $400 a week as manager of the Lone Star Wheels and Tires shop in Fort Worth.

But his seemingly quiet life came crashing down in September, a month after the embassy bombings in Africa, when prosecutors flew him to New York, charged him with lying to a grand jury and incarcerated him without bail. Court papers filed at the time of his arrest made clear that U.S. intelligence and law enforcement agencies had been tracking him around the globe for years.

Prosecutors, meanwhile, have hauled Moataz Hallack, the "imam" or prayer leader at the Center Street Mosque in Arlington, Tex., and Khader Ibrahim, the tire shop's owner, before a grand jury to answer questions about their links to Hage, a fellow worshiper at the mosque.

The FBI is also looking into a pair of wire transfers Ibrahim sent to Hage in Africa, one for $10,000 from a car accident settlement, the other for several hundred dollars from a sale of African semiprecious stones. Lawyers for both Hallack and Ibrahim deny that their clients are linked to terrorism in any way.

"It's clear they are following the money trail," Lynne Stewart, Ibrahim's lawyer, said of federal prosecutors.

She and other defense attorneys in the embassy bombings case say prosecutors are exaggerating the scope of al Qaeda's alleged conspiracy, damaging the reputations of countless individuals and American Muslims in the process.

"This is not a well-organized, hierarchical organization," Stewart said. "This is not the Pentagon. Since the prosecution wants to view it like that, they are sweeping with an enormously broad broom and pulling everyone into their net."

At one point in the indictment, prosecutors allege that Hage, when he was still in Kenya, received a document in 1995 about Rahman's trial in New York. He was directed to hand-deliver the document, the indictment says, to Osama bin Laden. It had arrived from California. The sender: Ali A. Mohamed.

Former U.S. Army Sergeant

Mohamed, a major in the Egyptian army, immigrated to the United States in 1986 and continued his military career. He joined the U.S. Army and was eventually assigned to the John F. Kennedy Special Warfare Center at Fort Bragg, N.C.

Within a year of his discharge in 1989, according to the indictment, he was training al Qaeda members in Afghanistan and Sudan and traveling the world for bin Laden, delivering messages and conducting financial transactions.

In 1991, the indictment alleges, Mohamed personally escorted bin Laden from Pakistan to Sudan, where he helped train bin Laden's bodyguards. Three years later, Mohamed used his U.S. passport to enter the U.S. Embassy in Nairobi on an apparent surveillance mission, the indictment states.

He was, by then, talking to al Qaeda members in Kenya about attacks on the embassy and other U.S., British, French and Israeli targets in Nairobi, the indictment says.

Back home in California in 1994, Mohamed soon found the FBI knocking at his door. Agents wanted to know what connections he had to those charged back in New York with plotting to blow up the World Trade Center. He was, at the time, listed as a defense witness in Rahman's pending trial. And he remained a figure of fascination to the FBI.

In 1997, court papers say, Mohamed told FBI agents that he had been in Somalia in 1993 and knew that bin Laden's operatives were responsible for killing 18 U.S. servicemen in a firefight in Mogadishu during the U.S. mission to support humanitarian relief operations and arrest warlord Mohamed Farah Aideed.

Shortly after the embassy bombings, those papers say, Mohamed also told an FBI agent that "he knew who had carried out the recent bombings but would not provide the names to the United States government."

He was arrested in September and held in secret in New York until he was added as a defendant to the bin Laden indictment in May, charged in a conspiracy to "murder United States nationals anywhere in the world, including in the United States."

Orlando Taxi Driver

Finally, there is Ihab M. Ali.

At the Metropolitan Correctional Center in Manhattan, the taxi driver from Orlando lives under the same maximum security conditions as Mohamed, Hage and other jailed defendants in the embassy bombings case, even though he hasn't been charged in the conspiracy.

Ali left the United States in 1989 and spent several years helping Afghan refugees on the Pakistan border before returning to Central Florida. Beyond the possible Afghan connection to supporters of bin Laden, prosecutors have yet to explain why they have chosen to squeeze Ali.

But something is known about al Qaeda's ties to Orlando, which involve Hage, the Texas tire store manager.

In February 1997, the indictment states, Hage, then in Kenya, sent a coded fax to an unnamed "co-conspirator in Orlando" saying that he had just returned from a meeting with bin Laden's military commander, Muhammed Atef, in Pakistan.

Five days later, according to the document, the co-conspirator replied in code with an offer of support for bin Laden. Another coded message from the co-conspirator in Orlando followed five months later, the indictment says. This time, there was a warning: "Be careful about possible apprehension by American authorities."

AL QAEDA AROUND THE GLOBE

Authorities believe al Qaeda worked on its own and with the Egyptian Islamic Jihad and other alleged terrorist organizations in at least 24 countries, including the United States.

The following suspects have been named by the U.S. Attorney's Office in indictments:

Name: Osama bin Laden

Status, location: At large, Afghanistan

Alleged role: Al Qaeda's leader

Name: Muhammad Atef

Status, location: At large, Afghanistan

Alleged role: Al Qaeda military commander

Name: Ayman Zawahiri

Status, location: At large, Afghanistan

Alleged role: Egyptian Islamic Jihad operative

Name: Mamdouh Mahmud Salim

Status, location: In custody, New York

Alleged role: Bin Laden lieutenant, financial aide

Name: Adel Mohammed Abdul Almagid Abdul Bary

Status, location: In custody, London

Alleged role: Managed training camps, guesthouses for al Qaeda

Name: Ibrahim Hussein Abdelhadi Eidarous

Status, location: In custody, London

Alleged role: Managed training camps, guesthouses for al Qaeda

Name: Khaled Fawwaz

Status, location: In custody, London

Alleged role: Bin Laden's spokesman

Name: Ali Mohamed

Status, location: In custody, New York

Alleged role: Al Qaeda trainer

Name: Wadih Hage

Status, location: In custody, New York

Alleged role: Bin Laden's personal secretary

Name: Fazul Abdullah Mohammed

Status, location: At large

Alleged role: Kenya bomber

Name: Mohammed Saddiq Odeh

Status, location: In custody, New York

Alleged role: Kenya bomber

Name: Mohamed Rashed Daoud Owhali

Status, location: In custody, New York

Alleged role: Kenya bomber

Name: Mustafa Mohamed Fadhil

Status, location: At large

Alleged role: Tanzania bomber

Name: Khalfan Khamis Mohamed

Status, location: At large

Alleged role: Tanzania bomber

Name: Ahmed Khalfan Ghailani

Status, location: At large

Alleged role: Tanzania bomber

Name: Fahid Mohammed Ally Msalam

Status, location: At large

Alleged role: Tanzania bomber

Name: Sheikh Ahmed Salim Swedan

Status, location: At large

Alleged role: Tanzania bomber

SOURCE: Staff reports