Osama bin Laden's global terrorist network has been constantly pressured and repeatedly compromised in the year since the fugitive Saudi multimillionaire allegedly masterminded the deadly truck bombings of two U.S. embassies in Africa, according to terrorism experts inside and outside the federal government.

But those experts worry that the Clinton administration's focus on bin Laden as the nation's number one terrorist enemy may have raised his profile in the Islamic world and increased the likelihood of attacks by him and his followers.

"He's become a charismatic leader like [Iran's late Ayatollah Ruhollah] Khomeini," said Kenneth Katzman, a Middle East analyst and terrorism expert at the Congressional Research Service. "This is what worries me. Bin Laden is the only one who's holding to this maximalist view: pan-Islamic and hard-core, no compromise with Israel, no compromise with the U.S., no compromise with Egypt. And he can back it up with force."

The twin truck bombs that detonated minutes apart outside the embassies in Nairobi, Kenya, and Dar es Salaam, Tanzania, on Aug. 7, 1998, killed 224 people, including 12 Americans, and wounded more than 5,000. Bin Laden and 16 alleged associates, including Egyptian Islamic Jihad leader Ayman al Zawahiri, have since been indicted by a New York grand jury on charges of plotting the embassy attacks.

U.S. officials note with obvious satisfaction that bin Laden's network has not injured a single American in the past year--a record they attribute to intensive U.S. intelligence, law enforcement and diplomatic efforts.

"We haven't killed him off," said Robert Oakley, a former State Department ambassador for counterterrorism. "But we've clearly reduced his ability to do things."

While some Clinton administration officials favor more aggressive attempts to attack bin Laden's hideouts in the mountains of Afghanistan, Oakley has counseled against it. "The risks of hitting the wrong place are very, very high--and you've got to assume it is going to be very heavily defended," he said.

Unwilling or unable to kill bin Laden, the U.S. government has sought to isolate and harass his organization, known as al Qaeda, Arabic for "the Base." Counterterrorism centers at the FBI and CIA--working closely with law enforcement and intelligence agencies around the globe--have detained, questioned or arrested dozens of suspected bin Laden operatives from Albania to Uruguay.

An alleged top bin Laden lieutenant, Mamdouh Mahmud Salim, was arrested last fall by German authorities and is one of five embassy bombing defendants in custody in New York. Another, Mohammed Saddiq Odeh, was apprehended by Pakistani officials, and a third, Mohamed Rashed Daoud al Owhali, was arrested in Kenya.

Authorities in London have three other defendants in custody.

The State Department, meanwhile, has offered a $5 million reward for information leading to bin Laden's arrest, and the FBI in June added him to its "10 Most Wanted" list--a reflection not only of the threat he poses but also of the FBI's increasingly international focus. It now has 1,383 agents assigned to counterterrorism in the United States and overseas.

Three weeks ago, President Clinton also banned commercial dealings between the United States and Afghanistan's ruling Taliban militia, accusing the Taliban of harboring the renegade millionaire. Until then, leaders of the Taliban had denied knowing bin Laden's whereabouts. Two days after the sanctions went into effect, they admitted that he was living in the portion of Afghanistan under their control.

"If we're able to keep the pressure on him--following this diplomatic, political strategy--bin Laden will ultimately make a mistake," said one senior Clinton administration official. "Something will break."

But others contend that the government, in its quest to hound bin Laden, has turned him into a rallying point for anti-Western sentiment.

"I have clearly told the Americans that they have . . . made Osama bin Laden a great hero in the Islamic world with these pressures and economic sanctions," said Abdul Hakeem Mujahid, the Taliban's chief representative at the United Nations.

Former CIA official Milt Bearden, who ran the agency's covert campaign to arm the Afghan mujahedeen fighting Soviet troops in the 1980s, agrees. "One should go to the refugee camps throughout Pakistan and find out how many boy children have been named Osama since last August," he said. "That's scary."

A year of harassment by U.S. intelligence and law enforcement agencies may have weakened bin Laden's ability to strike, said Katzman, "but he's stronger in popularity," which presumably helps al Qaeda raise funds and recruit supporters.

And there are signs that he still could strike at any time. "If his cells are surveilling our embassies in Africa," asked Katzman, "how constrained is he?"

Indeed, the government's campaign against bin Laden is now highly defensive, involving expensive efforts to harden U.S. diplomatic posts against attacks and a willingness to shut them down on a moment's notice.

In late June, the State Department temporarily closed embassies in six African nations--Madagascar, Gambia, Togo, Liberia, Namibia and Senegal--because of indications that they were under surveillance by members of bin Laden's network. All told, the State Department has closed embassies and consulates more than 60 times in the year since the African bombings.

Even the FBI halted public tours of its headquarters in Washington this month after receiving what it considered credible information about a potential attack by bin Laden operatives to mark the anniversary of the embassy bombings, according to a senior FBI official.

By far, the most chilling threat presented by al Qaeda involves its possible acquisition of chemical weapons. The government's indictment against bin Laden and 16 other defendants in the embassy bombings case states that he has "made efforts to obtain the components of chemical [and] nuclear weapons."

Katzman, citing numerous news reports, said he believes "we have to assume that he has some rudimentary chemical capability."

One U.S. official said that bin Laden has "actively sought to acquire chemical weapons, and it is possible that he could conduct some type of [small-scale] chemical attack."

But no evidence exists, the official added, to suggest that bin Laden's network has "weaponized" nerve gas or other chemical agents in a form that could kill large numbers of people.

Once, only the state sponsors of terrorism--a short list that includes Iran, Iraq, Sudan, Syria and North Korea--were thought capable of organizing chemical attacks.

But a year after the embassy bombings, bin Laden has eclipsed all of the state sponsors in the eyes of those in the U.S. government responsible for combating terrorism.

Brian Jenkins, a terrorism expert at the Rand Corp., wonders whether such preoccupation is wise. "This is a recurring pattern--we fixate on one individual, and chasing bin Laden becomes close to a single-minded pursuit: If we could only nail bin Laden, it would solve the problem," Jenkins said. "Well, there was somebody before bin Laden, and there will be somebody after bin Laden."

Special correspondent Colum Lynch contributed to this report from the United Nations.