From the WSJ Opinion Archives
AT WAR

The Assassination Plot That Wasn't
Sometimes, chasing faulty intelligence can pay dividends.

by RICHARD MINITER
Monday, October 4, 2004 12:01 A.M. EDT

(Editor's note: This is excerpted from "Shadow War: The Untold Story of How Bush Is Winning the War on Terror," which you can buy from the OpinionJournal bookstore.)

"When the subject came into the embassy in August 2002, he provided the names of nine Sudanese pilots who, according to the subject, were trained in Pakistan and recruited to conduct terrorist acts against the United States, including the White House."

--CIA report, March 16, 2003     

Washington:
As the first anniversary of the September 11 attacks approached, CIA and FBI officials were scrambling to stop a secret al Qaeda plot to assassinate President George W. Bush.

The public was never told why in August 2002 the new Department of Homeland Security raised the alert level from "yellow" to "orange"--signaling a high risk of terrorist attack. But the federal government had fresh, disturbing intelligence that suggested a major attack on America was slated for Sept. 11, 2002.

Certainly, the terror network likes to strike on politically significant anniversaries. The Aug. 7, 1998, bombings of U.S. Embassies in Nairobi, Kenya, and Dar Es Salaam, Tanzania--which killed a dozen American diplomats and 212 Africans--were carried out on the eighth anniversary of the arrival of American troops in Saudi Arabia.

Yet in the summer of 2002, American intelligence was not scrambling based on historical analysis or an inspired hunch. The CIA had received a warning that was specific and credible from a trusted source. And the plot, if it succeeded, would kill the president, destroy the White House, and shock the nation.

As it unfolded, a major CIA source would end up in an African prison, a luckless illegal immigrant would face America's new "zero tolerance" justice, and dozens of al Qaeda operatives would lose either their lives or their freedom. The "Mekki plot" would be a strange and ambivalent, yet crucial, victory in Bush's shadow war.

In August 2002, here is what the CIA thought it knew: Ali Osman Mohammed Taha, the first vice president of Sudan, was an active al Qaeda agent. Unbeknown to Sudanese president Omar al-Bashir, Taha had recruited 10 Sudanese men and sent them for flight training in Peshawar, Pakistan, in 1993. Their schooling was financed by al Qaeda and supervised by an Egyptian al Qaeda leader. Two years later, the 10 returned to Sudan and were "infiltrated" into the Sudanese air force. The report, from a CIA informant who was an officer in the Sudanese military, even supplied the full names of the 10 pilots. Two had subsequently died while serving in southern Sudan, where a bloody civil war had raged intermittently since 1955. Ominously, one of the 10, identified as Mekki Hamed Mekki, had vanished and was believed to be hiding in the U.S. The CIA's source said that Mekki's mission was to fly a small plane into the White House and kill President Bush--on Sept. 11, 2002.

The source, codenamed "M," had a long track record. For years, he had supplied information the agency considered reliable, and his position as a military officer seemed to give him access to unique intelligence. More chilling, U.S. government records confirmed elements of M's account.

American immigration records revealed that Mekki had arrived in New York on Sept. 27, 2000--around the time that the September 11 hijackers began to filter into the U.S. A visa had been granted by the U.S. Embassy in Cairo, Egypt, on July 18, 2000, for someone named "Makki Hamed Makki," perhaps an alternative spelling of Mekki's name. Translating Arabic names into the Roman alphabet frequently leads to variant spellings of the same name, although, as it later developed, Mekki was involved in a bit of subterfuge. By the time his tourist visa expired on Oct. 16, 2000, Mekki had disappeared. There was no evidence that he had left the country. According to M, Mekki had joined an al Qaeda sleeper cell.

The report sounded strikingly similar to an al Qaeda plan found on a laptop owned by Ramzi Yousef, the mastermind of the 1993 World Trade Center bombing. The computer, captured in a 1994 raid on the Doña Josefa apartments in the Malate district of Manila, Philippines, contained a detailed plot to pack a small plane with high explosives and kamikaze it into CIA headquarters. Yousef was captured in Islamabad, Pakistan, in 1995 and now is confined in a high-security federal prison. But his plans have a way of living on.

Years before Yousef was imprisoned, he and Khalid Shaikh Mohammed had dreamed up an early version of the September 11 attacks. The attack plan had germinated since 1992, was approved in 1998, and the first cell members were spirited into the U.S. in 2000. Was history repeating itself? Had another of Yousef's plans been put into play?

Huge measures had been taken to safeguard the president. Coast Guard boats patrolled the Potomac River. The Secret Service had initiated new, stricter procedures to protect the president and his family. Private planes had been banned from the skies over Washington. The Department of Homeland Security used helicopters to the patrol the capital's airspace, because jet fighters tended to stall out if they throttled back to the plodding speed of a Cessna or Piper Cub. Mekki was supposed to attack the White House in just such a small plane.

Even false alarms demonstrated the strong points of America's new security measures--as well as the holes just big enough for a small plane to slip through. On the night of the State of the Union address in January 2002, when President Bush was due to speak from the well of the House of Representatives, a single-engine plane flew into the "no fly" zone radiating outward from the Capitol, the White House and other federal landmarks. The pilot did not respond to repeated radio calls. He seemed to be making a beeline for the Capitol at the very moment President Bush was speaking.

"We read Tom Clancy just like everyone else," a Department of Homeland Security official told me. As jets scrambled and helicopters closed in, Homeland Security feared a terror strike modeled on Clancy's novel "Debt of Honor." In the book, a commercial plane smashes into the Capitol during the State of the Union address, killing the president and many members of Congress.

Homeland Security helicopters directed the plane to land at a nearby airport. Inside was an embarrassed Maryland state trooper, an amateur pilot who simply wanted to show his son an aerial view of the Capitol dome lit up at night. He had no idea that the president was delivering a speech or that air travel over Washington, was restricted to government aircraft. The incident revealed that air defenses still needed to be tightened. Fewer than nine months later, they seemed to be on the verge of being tested again--this time for real.

Meanwhile, the FBI had lost Mekki's trail. He had given one address on his immigration forms and quickly moved to another. The tenants at his first address claimed to have no idea where Mekki was--only that he didn't live there. He did not show up in a national search of phone directories or in Internet searches. If the FBI had searched state driver's license records, it would have found him in minutes. Like Mohamed Atta, Mekki had a valid driver's license in his own name.

The CIA was canvassing all of its sources and begging for help from friendly intelligence services. No luck. And the agency's source who had filed the report, M, had been sent on a military mission far from Khartoum. M could not be reached without compromising his identity as an informant and risking his life.

Seven time zones away, CIA Director George Tenet was demanding regular updates. "The station chief's balls were really getting squeezed," said a European consultant for the government of Sudan, who was briefed on the Mekki plot as the drama unfolded. "They had to do something."

Khartoum, Sudan:
The phone rang after midnight at the home of a senior Sudanese intelligence officer. We will call him "Sayed." The duty officer who, with his peers, covers the phone 24 hours a day, said the CIA chief of station urgently desired a meeting.

"Now?"

"Yes, now."

Sayed, who supplied much of this account in an exclusive interview with me in Khartoum, agreed to drive over to the rambling, rundown complex that was home to Sudan's external intelligence service, known as the Mukhabarat (Sudan's intelligence service is now housed in a new tower with Ikea-like furniture). He found the American official waiting.

The CIA was desperate and the clock was ticking. Now, in the last week of August 2002, the station chief had decided to take a calculated risk and ask the very government that was suspected of hatching a plot to kill President Bush to help locate the man thought to be the ringleader.

This was not an easy decision. Sudan had been on the U.S. State Department's list of state sponsors of terror since 1993. Osama bin Laden had lived there from April 1991, when he had been welcomed at Khartoum Airport's VIP terminal by Hassan al-Turabi, then speaker of the Parliament, to May 1996, when he was expelled at the request of the Clinton administration. Khartoum had sponsored an annual gathering of Islamic terrorists--every group from Hamas to the Moro Islamic Liberation Front--until 1996, when the conference was shut down at the request of the American government. The U.S. also believed that Sudan hid terrorist training camps and a chemical weapons program--allegations that later turned out to be false.

Relations between the United States and Sudan had long been "in the deep freeze," as one intelligence source put it. The U.S. had applied severe economic sanctions in 1997 and never eased them. A coalition of human-rights and Christian groups made it politically difficult even to consider normalizing relations. Both Republicans and Democrats in Congress were pressing for tougher measures, on the grounds that Sudan's civil war had led to human rights abuses and modern-day slavery. (While these tragedies are real enough, the role of the rebels in both was overlooked.)

Sudan's many offers to help the U.S. fight terrorism were spurned by the Clinton administration. In February 1996 and again in March 1996, senior Sudanese officials in Khartoum and Washington offered to arrest bin Laden and turn him over.

The Clinton administration debated the proposal and ultimately turned it down. The reasons range from the political to the procedural. If the U.S. took custody of bin Laden, some administration officials feared, President Clinton would be accused during the 1996 presidential campaign of negotiating with a terrorist state. Others feared that a lack of airtight evidence to guarantee a criminal conviction might lead to an embarrassing acquittal for bin Laden.

Both of these objections could have been easily finessed by asking Sudan to transfer bin Laden secretly outside of legal channels. This is known as a "rendition." Renditions of drug lords were not unknown in the Clinton years, but the Clinton team never seemed to have considered the option in bin Laden's case. Sudan might have viewed it favorably; it had rendered the infamous terrorist Carlos the Jackal to France in 1994.

But, instead, in May 1996, the Clinton administration asked Sudan, through a friendly Western intelligence service, to expel bin Laden. He left within weeks for a haven in the hills of Afghanistan.

In 1997, Sudan's president wrote a formal letter to President Clinton, offering access to Sudan's voluminous intelligence files on senior al Qaeda figures. Mr. Clinton never responded. (I saw some of these files in 2002; they are a treasure trove of important details on bin Laden and his associates.)

In 1998, Sudan captured two of the planners of the East African embassy bombings. When Gutbi al-Mahdi, then the Sudanese intelligence chief, offered to turn over the two suspects to the FBI, the bureau was denied permission to travel to Khartoum to take them into custody. The White House had its reasons. Several days after spurning the offer, American cruise missiles destroyed the al-Shifa pharmaceutical plant in the Sudanese capital.

Poor intelligence--some of it based on fraudulent reports from paid informants inside Sudan--hoodwinked the U.S. into believing that the plant was owned by bin Laden and was being used to make chemical weapons. Exhibit A was a soil sample said to contain EMPTA, a precursor to VX nerve gas. But the sample could not have come from inside the plant; the ground there was covered entirely in concrete, as I noted when I toured the wreckage. And the soil sample was later shown to contain Round-Up, a common weed-killer, not EMPTA. Finally, records on file with the United Nations--which had a contract with the plant to produce medicines--revealed that it had been repeatedly visited by German and other European government officials and that neither bin Laden nor any of his front companies had any ownership stake. A classic intelligence failure.

Relations between the U.S. and Sudan had begun to thaw after President Bush was sworn into office on Jan. 20, 2001. Indeed, the shift in U.S. policy toward Sudan seems to have come directly from Mr. Bush. Sudanese foreign minister Mustafa Osman Ismail, sitting on the back lawn of his home overlooking the Nile River, told me an intriguing story that he said he received from a "reliable source": When Ugandan president Yoweri Museveni met with President Bush in the Oval Office in the spring of 2001, he gave the usual reasons why peace would be impossible between Christians and Muslims in Sudan. Bush was in no mood for business as usual. He interrupted Mr. Museveni, saying, "Those people need peace." There was no mistaking Mr. Bush's tone. The Ugandan president, whose government had supplied and funded the Christian rebels for years, got the message. Peace talks resumed.

While the Clinton administration had tried to unilaterally isolate and even topple the regime in Sudan, the Bush administration was trying a more realistic approach. The National Islamic Front, which ran Sudan, was not going anywhere. The Bush team, working with the European Union, initiated a strategy of limited, incremental engagement. Concerns about terrorist training camps and weapons of mass destruction were patiently investigated. Ultimately, six teams totaling 145 people would visit Sudan in the two years ending in 2002. Bush appointed a special envoy, former senator (and now U.N. ambassador) John Danforth, to broker peace talks. The talks would eventually succeed.

Walter H. Kansteiner III, assistant secretary of state for African affairs, met secretly with Sudan's foreign minister in Nairobi, Kenya. They met again in London before Sept. 11. These meetings are reported here for the first time. The U.S. wanted to work closely on terrorism and on promoting peace.

Intelligence cooperation was slowly resumed. On May 17, 2001, the CIA and Sudanese intelligence began a hesitant and cautious collaboration on counterterrorism. On Sept. 12, 2001, Sudan provided the CIA with a list of 26 names of al Qaeda operatives it believed were inside Sudan. Khartoum offered to make them available for questioning. In the following months, all 26 were questioned by the CIA and FBI. Some were held and others put under surveillance. "This is probably the best set of leads that the CIA got in the hours after September 11," said David Hoile, a British consultant to the Sudanese government. "It was the beginning."

The CIA held eleven meetings with its Sudanese counterpart from January 2001 to August 2002, according to Janet McElligott, a onetime lobbyist for Sudan in Washington who maintains friendly ties with Sudan's intelligence services. Mr. Hoile puts the number of meetings between Sudanese intelligence and the CIA and FBI at "close to 100" from September 2001 to June 2004. Still, the agency remained suspicious of Sudan, which had long been tied to terrorism.

Sudanese officials say that they wondered whether American attitudes would ever really change. Neither side suspected that the "Mekki plot" was about to transform their relationship. And never before had a CIA official requested an "urgent meeting" in the middle of the night.

The CIA chief of station gave Sayed a carefully scrubbed account of an alleged plot to crash a plane into a major U.S. government facility, referring to his secret source only as M. He presented Sayed with a list of 10 suspected pilots, including Mekki.

Sayed was guarded. "It was not the first wild allegation I'd heard from the Americans," he told me. Previous "wild allegations" included two post-September 11 sightings of bin Laden; one in Darfur, in the remote reaches of western Sudan, and the other in Juba, in its tropical, war-torn south. Both were found to be false. "So I was not astonished."

But this was different. The account was detailed and contained many checkable facts. If it were true, it would strangle any hopes for better relations with the United States. If it were false and could be proved so, it might lead the Americans to reconsider their stance. So, for Sudan, it was an opportunity wrapped in a crisis.

Then the station chief asked his urgent question: Will you help us?

Early the next morning, Sayed tracked down Mekki's commanding officer. He was told that Mekki had indeed trained as a pilot in Pakistan, but at his own expense. Until 2000, it was fairly common for Sudanese men seeking military careers to arrange their pilot training in Pakistan; Sudan's military has a relatively small training budget and preferred to recruit pilots who already knew how to fly. There was no evidence, the commander said, that Mekki had received help from al Qaeda. Oh, and Mekki had gone AWOL in July 2000. So far the CIA story was checking out.

Sayed placed a rush order for the military records of all 10 pilots the CIA had named. Within hours, a stack of files had arrived via military courier. Sayed started reading.

That night, after evening prayers, Sayed met with the station chief. He got right to the point. "The backbone of the story is 100% true," he said. The names of the 10 pilots were accurate. They were indeed sent to Pakistan for training in 1993. They had returned to Sudan in 1995. Shortly thereafter, all 10 were inducted into the Sudanese air force. The two pilots who were reported to have died actually did perish in the south. And, as the CIA feared, Mekki Hamed Mekki was in fact "absent without leave" from the air force, disappearing sometime in July 2000. So far the CIA's report was dead accurate, Sayed said.

But two vital facts were wrong. The pilots had not received financial aid from al Qaeda or any bin Laden front group (they had asked their families for the money), and they had not trained in Pakistan under an Egyptian, let alone an Egyptian member of al Qaeda, but under a Pakistani who was a veteran flight trainer. Finally, there was no known relationship between these men and al Qaeda or Osama bin Laden.

The CIA official was unconvinced: "You're just trying to protect your government."

Sayed understood the situation perfectly. The CIA official believed that Sayed was either only admitting what he knew the U.S. already knew or was attempting to deceive the agency by acknowledging the less damaging parts of the story while denying the rest. Certainly, the station chief was not going to bet his career on an assurance from a Sudanese intelligence official he barely knew--especially when the president's life was on the line. The only solution was to help the CIA find Mekki. "OK, let me start the search."

On a side street in Jimaiab, a poor neighborhood at the edge of Khartoum, Sayed found the modest home of Mekki's parents. Mekki's father, a respected high school principal, was polite but unhelpful. He said that he had no information on his son--only that he had left Sudan. Sayed got the impression that Mekki and his father had fallen out over something. But what?

Having a deep understanding of the dynamics of Sudanese Arab families, Sayed sought out Mekki's sister, saying, "You know where your brother is, don't you?"

With some reluctance, she explained the family history. Mekki wanted to chase the American dream, but his father thought it was dishonorable to desert the Sudanese military. It would make Mekki a criminal and bring shame on his family. Mekki, however, had no patience and, in his mind, no future. Father and son parted on bad terms. Mekki's sister concluded, "You can't tell [my father] that we're talking, because my father has forbidden it."

Just as Sayed had suspected, she was in furtive contact with her brother. He gently asked how he could reach Mekki.

She grudgingly provided a phone number--in North Carolina.

As soon as the time difference allowed, Sayed dialed the number. The man who answered spoke Arabic with a Sudanese accent. Sayed asked for Mekki.

The man did not want to help. Like many Sudanese, he was not in the habit of telling government officials the whereabouts of his friends. Sayed played his cards carefully. "Don't worry. The only reason we are looking for him is that there's a problem with his father. He doesn't get along with his father. His sister gave us this number. We're trying to do good with this." Sayed knew this would have the ring of truth.

"Well, why does the FBI want him?" The man told Sayed that a letter had arrived for Mekki from the FBI. Tactically, this was a stupid move on the part of America's largest domestic counterterrorism unit and a sign of desperation. It only complicated things.

Sayed bluffed. "Oh, it's probably some immigration thing that doesn't have anything to do with us."

Greensboro, N.C.:
United Yellow Cab No. 50 was parked under the branches of a tree near a Harris Teeter store, along a shopping strip on West Market Street. Three other taxicabs were parked behind it. Inside No. 50, four immigrants from Sudan were passing the time, waiting for the radio dispatcher to send one of them a pickup call. One of the four men, Zaher Altahair, recalls, "We were just talking, weather, sports . . ."

Suddenly two cars and a sport-utility vehicle roared in, blockading the taxis. Four men in ties emerged. One was FBI special agent Michael Knapp.

"Let me see your licenses," Mr. Knapp demanded.

The lanky man in the driver's seat showed Mr. Knapp a valid North Carolina driver's license. It featured his picture and his real name, in full: Mekki Hamed Mekki.

North Carolina is one of only three states that grants driver's licenses without asking for a Social Security card or other proof of U.S. citizenship. This policy is supposed to encourage road safety and compel illegal immigrants to get car insurance. Whatever its merits, the policy made it easy for Mekki to get a license and a job. He even enrolled as a student at North Carolina Agricultural and Technical State University, where September 11 planner Khalid Shaikh Mohammed had studied in the 1980s.

Mr. Knapp wasn't satisfied. He wanted to make sure he had the right man. For all he knew, Mekki could be the Sudanese equivalent of "Smith." When he demanded further proof of identification, Mr. Knapp was setting a trap for Mekki, whether either one of them knew it or not.

Mekki offered to drive Mr. Knapp to his apartment. The address was in the heart of a Sudanese immigrant enclave. Indeed, so many of the estimated 3,000 Sudanese who live in Greensboro reside in this neighborhood that it is known locally as Omdurman, after a district in Khartoum.

Mekki pulled up in front of the Colonial Apartments at 402 Montrose Drive. He lived there with three other Sudanese-born taxi drivers.

Once inside apartment F, Mekki opened a small closet door and withdrew a black plastic shopping bag, which is where he kept his important papers. He produced a valid Sudanese passport and U.S. immigration documents indicating that he had filed for a green card under 20 different versions of his name. Unwittingly, Mekki had just handed a FBI special agent proof of immigration fraud, a criminal offense. This evidence would become more important later, but right now all Mr. Knapp cared about was finding out whether this immigrant taxi driver was plotting to kill the president of the United States.

Mekki was handcuffed and led outside. His taxi would remain parked on Montrose Drive for days--a memorial to an ordinary immigrant life stopped short by extraordinary circumstances. Eventually, he arranged to lease it to a Sudanese friend and used the money to pay his legal bills.

The interrogation of Mekki began almost immediately. The more Mekki talked, the less the FBI believed.

In their initial conversation, Mekki seemed to be hiding something. Three consecutive polygraph tests confirmed these suspicions. He was lying and covering up--but what?

Mekki told the agents the kinds of things poor Africans say when they are trying to secure asylum in the U.S. He said that he was forced to commit war crimes in Sudan's civil war and that when he refused he was repeatedly tortured. Fearing that the government wanted to kill him and his family, he fled. This is precisely the script someone uses to win political asylum, and the multiple, fraudulent U.S. immigration forms demonstrated that Mekki was an expert at playing the system.

When asked about bin Laden, he said he knew nothing about him. As it happened, this was the truth, but it was hidden in a welter of lies.

As a result, the FBI could not rule out that Mekki was part of a sleeper cell that was plotting a fiery, murderous atrocity. The FBI desperately needed to know the numbers and location of the other cell members and was fully aware that Mekki's arrest might have triggered a final countdown.

It was time for the CIA to take another calculated risk--an unprecedented one.

Khartoum, Sudan:
The lobby of the Khartoum Hilton is never quiet or empty after evening prayers. It offered the finest decor available when it opened in 1977 and has changed little since. Translucent yellow globes dangle from long chains over a rectangle of couches and uncomfortable bamboo chairs. Here men in white turbans banter with chain-smoking arms dealers, long-haired nonprofit directors, and cigar-puffing reporters.

No one noticed the tall man in the blue safari suit glide in. He found the CIA official waiting on a couch.

This time the American had a surprise for his Sudanese counterpart: a copy of the cable that had launched the global manhunt for Mekki. But first the CIA officer had a question: "What made you think this information was false?"

"Well, because this is typically Sudanese."

The informant, Sayed explained, was getting paid to provide information. If he didn't have any genuine intelligence to offer, he had a powerful financial incentive to make something up. The Sudan CIA station paid anywhere from $100 to $400 per report. The per capita income in Sudan is estimated at $1,400 a year.

Paying for information is risky enough, but, in Sudanese terms, the agency was paying so much it was certain to corrupt its sources. A retired CIA officer who once supervised all of its Near East stations told me that it is never wise to pay for reports at the beginning of a relationship with an intelligence source. The truth can usually be bought by other means than money (such as appeals to pride, patriotism or recognition), while false reports are always expensive. "You introduce money into the relationship only later," he said, "as a control factor." But the Sudan station had experienced a rapid turnover since 1996 and there were few veterans to warn of the dangers of payouts to sources.

Here is how Sayed remembers the conversation:

Sayed asked, "Have you checked out the source who gave this to you?"

"Well, he's been a source for years."

"Do you think that could be why there are some problems between the CIA and the Sudanese? Why don't you check out your source?"

Perhaps the CIA still believed that Mekki was going to murder President Bush; his lie detector tests clearly showed evidence of deception.

Sayed reminded the station chief that the CIA had been repeatedly duped by false reports from Sudan. One report in 1995 warned of an assassination attempt on then-National Security Adviser Anthony Lake. Mr. Lake and his family were moved to a secure location and the Secret Service stepped up security. The threat was later proved false. When I interviewed Mr. Lake in 2002, he confirmed the circumstances but claimed that he didn't give the report much credence at the time and later joked about it. It was one of many small intelligence failures out of the CIA's Sudan station. A few years later, when several CIA sources failed their lie detector tests, the agency was forced to "withdraw" more than 100 reports about Sudan. Now it looked like it might have to discard one more.

"There is strong evidence that M is lying," Sayed said. "Not only should you look at this story, but what we would do in our service is look at all of the stories he gave us. We'd suggest that you do that and go find out how many of them turn out to be true."

"Well," the station chief said, "we agree with you and we're going to do that." The CIA officer then gave up the name and rank of his source.

"This was the turning point in the relationship with the Americans. It is not normal that an agency gives up a source," Sayed told me. "I praise him [the station chief] for doing this."

It turned out that M was a Sudanese army captain named Bilal Awad Sulayman. Together, the two intelligence officers conspired to snare him.

The next day, still carrying a travel bag from his assignment in the southern war zone, Bilal was met by plainclothes intelligence officers and escorted from the Khartoum military airport to the Mukhabarat headquarters. If he was nervous or had questions, he was too clever to ask his escorts.

Eventually he was ushered in to see Sayed. Bilal demanded to know why he had been brought in.

Sayed expertly seized control. "You have been chosen for a special intelligence assignment. Ask no questions. I need you to go into the next room and answer truthfully all the questions asked of you by the people who are in there."

Bilal said nothing. He had only one option--to brazen it out and hope that, like Benedict Arnold, he would survive.

Sayed told Bilal to change out of his military uniform and into civilian clothes. As the captain snapped back the locks on his suitcase, Sayed stepped outside.

A few minutes later, Bilal emerged in "civvies." Sayed pointed to the closed door of a conference room. Bilal twisted the knob, not knowing what to expect.

He was surprised to find two middle-aged Americans inside. One was setting up a polygraph, laying out the lie detector's telltale wires and cords. The other addressed him in clear, non-Sudanese Arabic. They identified themselves as CIA officers.

CIA? Working inside Sudanese intelligence headquarters? Bilal couldn't believe it. "It was a great shock to him," Sayed said dryly.

For more than an hour, Bilal sat in stony silence as an old CIA hand tried to coax and coach him. Bilal's thoughts must have raced. Perhaps it really was some kind of Sudanese intelligence operation. Or was it a trap?

The polygraph operator was a very skillful interlocutor. He had interrogated people for the CIA for some 26 years. We don't know what he said, but we know the result. Bilal broke.

Wires were attached to his fingers, forehead and chest. The polygraph needles jumped and the readings scrolled out. The interrogation lasted 3 1/2 hours.

While Bilal debated his nonexistent options, Sayed met with the station chief in another office in Mukhabarat headquarters. "You might assume that this man is not the right one, so I wanted to put all of those suspicions aside," Sayed said.

He picked up a military ID card, which he had plucked from Bilal's uniform pocket. The station chief had a photocopy of Bilal's ID card that had been made about two years earlier. They put the two side by side. A perfect match.

If the station chief suspected that the Sudanese had supplied a ringer, he did not let on. But he had no doubt now that the man in the next room was M, his source. It would be dawn before he knew whether his source was reliable--and whether the president's life was actually in danger.

Early the next morning, CIA officials pored over the polygraph results. There was no doubt: Bilal had been lying to the CIA for years. There was no plot to kill the president. It was an ingenious scam, a great lie propped up by many small truths. Or, as a CIA polygraph report concluded: "Information that subject had concerning an attack on the White House was a fabrication."

Bilal had a mix of personal, financial, and political motives. He disliked Mekki and some of the other 10 pilots he had named; he was paid hundreds of dollars for each false report and he liked the folding money. He was in the midst of building a large house in Khartoum that was "very expensive and would have been beyond the reach of an army officer," Sayed told me. The house could not have been built with family money: Bilal never married, and his parents, who were divorced, had little themselves. "Lies and CIA cash built that house," David Hoile told me.

Bilal also had ideological and personal reasons to detest the regime. His family was known for its history of antigovernment sentiments. And he smoked hashish, a serious crime in the Sudan--and the threat of punishment no doubt concentrated his mind. Finally, the CIA had promised him that if things got too dangerous for him in Sudan, the agency would give him a U.S. visa and help him get a job in the United States. If Bilal had had the wit to lie about assassination attempts on his own life instead of George W. Bush's, he might have moved to the green, prosperous suburbs of Washington.

Instead, he never made it out of Sudan. In the coming weeks, he would be tried and convicted of espionage. Today he is incarcerated in the al-Khobar prison, an old British-built penitentiary with whitewashed walls and narrow guard towers in Khartoum. "When we recruit a source," a former CIA station chief explained to me, "we are seducing people into betraying their country." Bilal was a traitor who lied to the CIA and got caught. There was no mercy for him now.

Some might feel sympathy for Bilal, thinking he was simply a poor man on the make. Citing such impersonal forces--such as poverty--is always a dodge for individual responsibility. Bilal swore an oath to defend his country and he betrayed it. He also betrayed the trust of his American friends for profit and self-aggrandizement. His lies led hundreds of FBI, CIA and Homeland Security staffers to waste their time on a plot conjured out of his imagination. As any fireman knows, a false alarm across town can keep the fire department from responding if a fire starts next door. His fabrications temporarily poisoned relations between the U.S. and Sudan, at the very moment when President Bush badly needed allies in East Africa to wage war on al Qaeda.

Meanwhile, on Sept. 13, Mekki was being held in Forsyth County Jail in Greensboro, N.C., awaiting arraignment. He had no idea how his freedom had been taken, through incredible circumstances, by his old acquaintance Bilal.

Greensboro, N.C.:
U.S. attorney Anna Mills Waggoner heard the news from the FBI. There was no easy way to explain that the bureau--indeed, the entire federal government--had been duped by false intelligence. Mekki was not at the center of an al Qaeda plot to kill President Bush; he was a pawn in a scam to defraud the CIA.

In principle, Waggoner could have decided not to pursue the case against Mekki at that point. But leniency was actually against U.S. policy.

The head of the FBI's international counterterrorism division, Michael E. Rolince, had written a secret seven-page document distributed to all federal prosecutors. It was used to secure the strongest sentences possible, even for minor offenses, if a link to terrorism were suspected.

Attorney General John Ashcroft publicly endorsed this policy in a speech before the U.S. Conference of Mayors in October 2001: "Robert Kennedy's Justice Department, it is said, would arrest mobsters spitting on the sidewalk if it would help in the battle against organized crime. . . . It has been and will be the policy of the Department of Justice to use the same aggressive arrest and detention tactics in the War on Terror. Let the terrorists among us be warned: If you overstay your visa--even one day--we will arrest you."

Mekki had overstayed his visa by almost two years. The fraud charges would be harder to prove.

"Does the government intend to pursue this case?" asked U.S. Magistrate Russell Eliason.

Assistant U.S. attorney Patrick Auld had his marching orders. "Yes, your honor, and there's the possibility that other charges will be brought."

Actually, as the judge hinted, the government's case was weak. Even Special Agent Knapp admitted under oath that the immigration processing center in Lexington, Ky., had no record of Mekki's fraudulent applications. The facility regularly trashed all applications it denied. So there was no hard evidence, aside from the documents handed over by Mekki, that the defendant had defrauded anyone.

Gregory Davis, one of the public defenders fighting for Mekki, was outraged. "It's almost like saying somebody's dead and there's no body," he said. "I think they've jumped the gun and held him . . . when there was really some other motive for holding him." But, as far as I have been able to determine, no one ever told Davis or Mekki the true story.

Some 40 of Mekki's friends, mostly Sudanese-born cab drivers, sat in the courtroom. They had helped raise almost $2,500 for Mekki's legal defense, a princely sum in the minimum-wage world. Outside the courtroom, they told reporters that the prosecution of Mekki was more evidence of anti-Muslim bias in post-September 11 America. The familiar script of grievance and selective prosecution would take over. One of their own was being sent away, and to them it was easy to suspect persecution--a bitter little taste of what they had left behind. After all, the government wasn't deporting Mexicans and other Roman Catholics who entered the country illegally, only hardworking Muslims like Mekki.

A moment's reflection would dissolve these claims. More Latin Americans are deported from the U.S. than people from any other region in the world. Besides, no one argues that immigration cases should be litigated using some form of affirmative-action quota system.

Few knew or admitted that Mekki had supplied physical evidence of and admitted to committing a number of immigration crimes. These facts might not count for much in Greensboro's Omdurman. Illegal aliens from all over the world had done the same thing, including perhaps Mekki's neighbors. To them, it was a paperwork violation. And it was. But as federal prosecutors could point out, similar violations had helped cost 3,000 people their lives on September 11, 2001.

And, in the unlikely event Mekki did turn out to be a terrorist, releasing him would shame the Justice Department and cripple some careers. The easy decision would be to let the wheels of justice grind on. That is what happened.

In an ideal world, Mekki might have been allowed to stay in the U.S. After his unlawful entry, he had done all the right things: He worked hard, paid his bills, helped others, and pursued an education. He was unknown in both the police department and the welfare office. Government certainly has the power of selective prosecution; it does not have to charge every lawbreaker it runs across. It can set priorities. It cannot possibly prosecute every malefactor; there isn't money enough or time. But that is not to say that Mekki was not guilty, only that he was unlucky.

Welcome to the post-September 11 world. It isn't ideal. It is full of hard choices. A nation at war is not disposed to take chances on mercy. Remember the visible and invisible aspects of such tough law enforcement. We see Mekki and his destroyed life. We don't see the terrorists who might have been deterred when his sad story circulates in the immigrant community--or the lives saved by tougher immigration measures. Not everyone who cheats the system, like Mekki, is harmless.

Due to poor intelligence, the CIA and FBI had spent thousands of man-hours and hundreds of thousands of dollars to arrest a taxi driver with a stack of falsified immigration documents. The CIA's fabricating source was imprisoned and Mekki was on his way to being deported.

Yet strangely, the sad Mekki case was a net victory in the war on terror--at least from the viewpoints of the CIA and the Sudanese.

The so-called Mekki plot pushed the CIA to purge its poor intelligence sources in Sudan and led to a newer, stronger relationship with Sudanese intelligence officers. As a result of this new cooperation, since September 2002 the Sudanese have arrested or detained for questioning nearly 70 al Qaeda operatives or associates, according to documents shown to me by a Washington-based Sudanese official who works with the CIA. Another 400 were expelled or handed over to other Arab security services, including those in Egypt and Jordan.

Mekki's sad case might even have prevented a covert war. In 2002, the Defense Department established the Combined Joint Task Force-Horn of Africa, known in Pentagonese as CJTF-HOA. Under the umbrella of U.S. Central Command, CJTF-HOA is headquartered in the small African nation of Djibouti, a former French colony on the Red Sea. With more than 1,800 soldiers, a multinational naval force, and several wings of attack helicopters, it is the largest American force deployed in the region since the ill-fated 1993 humanitarian effort in Somalia. Enhanced cooperation with Sudan was pivotal in persuading the Bush administration against deploying special forces in Somalia in 2003.

Like Afghanistan, Somalia is remote, lawless, and has a long history of Islamic radicalism. Al-Ittihad al-Islamiya, a Somali terror group modeled on the Taliban and associated with Osama bin Laden since 1993, had sheltered a number of al Qaeda terrorists. The Pentagon had planned for an assault on Somalia, using supplies and men from bases on the island of Diego Garcia. This buildup fooled several Arab intelligence services into believing that the Americans were simply overpreparing for the Iraq war.

But a stronger relationship with Sudan made other options more plausible. Sudanese intelligence understood the people and politics of Somalia very well. Many of the leaders of al-Ittihad al-Islamiya had studied in Khartoum and had been routinely watched by the Mukhabarat. While most of the money for the Somali terror group came from Saudi Arabia, Kuwait and other Persian Gulf states, many of its low-level staff had passed through Sudan.

In June 2003, the U.S. unveiled a $100 million package for fighting terrorism on the Horn of Africa, including coastal patrols and tighter border security.

With the help of several governments, dozens of al Qaeda operatives were captured and joint covert operations were carried out. Bin Laden's network was denied a critical base on the Horn of Africa. A shadow war against al Qaeda in East Africa was just beginning.

Mr. Miniter is author of "Shadow War: The Untold Story of How Bush Is Winning the War on Terror," just out from Regnery and available from the OpinionJournal bookstore.