"Financial troubles, immediate and continuing," Aldrich H. Ames said matter-of-factly, were what led him to spy for the Soviet Union and kept him at it for nine years until the moment of his arrest in February.

But money, he said, was not the only factor that allowed him to justify to himself what would become the worst security loss to the CIA in its 47-year history.

In a 90-minute interview at the Alexandria jail two mornings ago, Ames calmly attributed his ability to undertake what prosecutors described as "a crime that caused people to die" to a mentality that was shaped long before he began his work for the Soviets. He has been in the spy and counterspy business for 31 years, usually living a public life as a State Department official and a private one as a CIA operative. That dual existence, Ames said, long ago forced him to "compartment" his mind.

Asked how he could sell sensitive secrets, given his loyalty oaths, his feelings about his country, the futures of his wife and son, Ames leaned back and replied: "I tend to put some of these things in separate boxes, and compartment feelings and thoughts."

He was still, he said, mulling over a thought process that he repeatedly mused was "hard to ... articulate." But his conclusions thus far do not appear to include grief or contrition for the fact that his information apparently led to the deaths of at least four Soviets working secretly for the United States.

In his mind, Ames said, he and each of the Soviets he exposed were in the same game and ran the same risks as traitors to their own countries.

"I felt at least the way I'm selling these guys down the river, I'm exposing myself to the same fate."

What did he think, back in 1986 and 1987, when agents whose names he turned over to the Soviets -- some of whom were operatives he himself had recruited for the CIA -- began to disappear?

"I was pretty much able to compartment that. I had no personal relationship with any of those people. But other people, who were my friends and colleagues, had. And I think in a lot of ways I avoided, and continued to avoid, thinking about that.

"...I have a kind of empathy with what happened to them. I really felt that we had given each other, that what I had done to them was what was going to be done to me. That in a sense, my balance with them was even. Because in another of these compartments, it's pretty sure this was not going to go on forever."

The interview with Ames took place in a small, sealed room at the jail, furnished only with a round plastic table and chairs. Dressed in prison shirt and trousers, he did not look or sound like a beaten man; he spoke concisely and with apparent reflection, as if he had carefully considered and ordered his words.

He carried a sheaf of papers, but did not refer to them. His two lawyers present interrupted infrequently to caution him against discussing "classified" information.

Ames's clear, calm voice became animated only when he spoke of his wife, whom he charged was unjustly accused and used by the CIA to gain leverage against him, and of what he described as the broken faith between the senior CIA bureaucracy and the agents who "take the real risks."

Throughout his years of spying for the Soviets, Ames said, he was never afraid he would be detected by the CIA or FBI. The danger in his mind, he said, came from Soviet defectors.

"Initially, my only fear was that a KGB officer knowledgeable of my relationship with the KGB would defect or volunteer to us... . Virtually every American who has been jailed in connection with espionage has been fingered by a Soviet source," he said.

Ames dismissed the polygraphs he regularly was given as a CIA employee as "witch-doctory." "There's no special magic" in passing lie detector tests, he shrugged. "Confidence is what does it. Confidence and a friendly relationship with the examiner ... rapport, where you smile and you make him think that you like him."

Nor did he have difficulty explaining to the agency where he got the money the Soviets were paying him, a total of $2.5 million over the years, according to prosecutors. He was never asked, Ames said. "I never had to provide officially or unofficially any justification or rationalization. It was assumed, and I allowed it to be assumed ... that my wife's family had money. I never told anyone that Rosario {his wife} had inherited money from her father. But this was a reasonable assumption that people would make."

Ames clearly took pride in what he offered the Soviets. He said Wednesday that at the time he planned selling the first secrets in 1985, he was "one of the most knowledgeable people in the intelligence community on the Russian intelligence service. And my access to information and my knowledge of the Soviets was such that I could get virtually anything I wanted."

What he considered his access and ability, Ames believed, "also gave me the confidence and the ability, I thought, to have a brief relationship with them. And to control what I gave them, the information that would not do any damage."

Although Ames described his relationship with the Soviets as one in which he remained in control, the Soviet development of him from a onetime informer to perhaps the best multimillion-dollar investment the KGB ever made is almost textbook tradecraft.

He initiated the relationship by handing over the names of two Soviets to a still-unnamed Soviet Embassy official he was supposed to be recruiting for the CIA. The names, he insisted Wednesday, were inconsequential and probably already known to the KGB, and his motive was purely financial.

Within a month, he said, he began receiving payment of the $50,000 he had asked for.

But for the Soviets, it now seems clear that was merely seed money that might bear larger fruit given Ames's unhappy personal state.

At the time, Ames was under what he said was a great deal of personal pressure, including "my heavy drinking," and "my upcoming marriage to Rosario" after an expensive divorce.

He was also, Ames said, "increasingly alienated" by what he felt was politicization and neglect of tradition in the Central Intelligence Agency under then-Director William J. Casey. His mind-set was "like some relic preserved in amber," Ames said, "not because I'm so old, but because of the ideas that I hold. I think I'm much more typical of the people who were in the agency in the late '40s and early '50s than the people who are in it today. I've always felt very alienated from that standpoint."

Still, Ames said it was he who "around May of 1985" initiated their next transaction, one that he acknowledged represented a "fundamental shift in loyalty." "On my own volition, I packaged up the names, or in the absence of names, this information that was so damaging. I didn't put any preconditions on it, I didn't ask for more money. Although in my own mind I assumed that money would continue to come."

It was, Ames said, "the keys to the kingdom," made up of the names of all the Soviet agents he knew who were run by the CIA, FBI and other services.

Now due to spend the rest of his life in prison, Ames already has had a lot of time to rationalize what he did. While he freely acknowledges his need and desire for money, he also offers a complex and somewhat tortured explanation that has little to do with payment, or with loyalty to one country or another.

"When I said there was this strange transfer of loyalties," he explained, "it wasn't to the Soviet system, which I believe was a beastly, inhuman, nasty regime. It was indeed to the kinds of things that were happening." His loyalty, as he described it, was to a way of life, and a world he considered above the petty concerns of governments.

Americans were shocked in 1985 by discovery that the KGB had spies in the Navy, the National Security Agency and the CIA. This "great worry about how the U.S. had lost the spy wars," Ames said, was nonsense, and was being used for political reasons that helped him justify to himself trying "to even things out." He saw giving the Soviets the "keys to the kingdom," he said, as a way of "leveling the playing field. I knew that within the American intelligence community we knew damn well that the KGB wasn't going to town on us."

What the Soviets knew or thought of Ames's feelings cannot be known. What had to have been clear to them, however, was that they had a spy deep in the heart of U.S. intelligence. Within three months of his major delivery, Ames said, his Soviet contact gave him "a written message in which they expressed their gratitude and they said they had put aside $2 million for me. I was surprised and shocked," Ames said, "at the magnitude of that."

"I was deeply impressed by it," Ames said, "not just from a standpoint of greed, but that was very powerful." It allowed him, he said, to think about having "a child" with Rosario, and looking at "the long-term future, retiring and this sort of thing."

But in Ames's world, where the close relationship between case officer and agent is most important, the $2 million had another meaning. "In addition to this whole financial thing," he said, "they had put a little marker down in terms of mutual confidence and loyalty."

The KGB handlers also watched over him, "agonizing over every nickel they handed out, pleading and repeating and reiterating: 'Be careful, be careful. This is the way that people get caught.' "

At that point, in late 1985, Ames was hooked, not only by the money and loyalty to his Soviet handlers, but also apparently by his own ego. As he put it, "At that moment I was as good {an agent inside the CIA} as they could get, just about, for that brief period."

By the time he arrived in Rome for a three-year assignment in mid-1986, however, Ames said he had trouble keeping the compartments of his mind separate. It was hard, he said, to focus on what he was supposed to be doing for the CIA because he was spending so much time with the KGB.

"I must say that certainly in Rome, maybe I had a little trouble with that {CIA} compartment... . I felt and I wondered and still wonder to what extent my relationship with the KGB just kind of almost unconsciously hurt my ability to make the intellectual and emotional effort to do Soviet recruitment operations {for the CIA}."

The Soviets were sympathetic. "The Soviets and I discussed a number of times {in Rome} whether there were things they could do that would help me in my careers," he recalled. "And each time we discussed it, sometimes at their initiative, sometimes at my initiative, we came to the mutual agreement that it would be safer to do nothing."

The only regret he expressed during the interview concerned what he called his "sloppy, careless and reckless" keeping in his Arlington house of particularly damaging letters of instructions and accounting given to him by his KGB handlers in 1989 on the eve of his return to the United States.

The FBI's discovery of such evidence, he said, made the government less interested in his wife as a possible witness, thus making her more liable for time in jail.

"Had I done what a rational spy did," Ames said looking over at his lawyers, "I would have had better protection for her from the prosecutors."

It was similar sloppiness, he said, that had led her to find out about his espionage activities in the first place. That happened, he said, in 1992 when she found a note with Russian letters in an old wallet he had left in a drawer, he said.

Up to that point, he said, his wife had believed stories he fashioned especially for her about the origin of their sudden wealth.

He called it his "Robert from Chicago story" and it explained the first $50,000 as a loan from an old college friend whose girlfriend Ames had helped get an abortion. The later money, he said he told her, had come from investments Robert "and some of his associates asked me to manage and advise on" in Europe.

1962: Aldrich Hazen Ames joins the CIA as a clerk and works his way up to counterintelligence officer. In the late 1960s and 1970s, he works in Washington, New York and Turkey.

1981: Ames begins a three-year assignment in Mexico City, where he meets Maria del Rosario Casas, a Colombian embassy employee and academic.

1983: Ames is transferred to Washington, where he becomes chief of the Soviet Counterintelligence Branch in the Soviet/East European Division. He is supposed to review information from Soviet informers and analyze the backgrounds of Soviet intelligence officers recruited by the CIA.

1984: The CIA authorizes Ames to begin a series of meetings with Soviet Embassy officials in Washington to assess their likelihood of aiding the CIA.

APRIL 1985: Ames passes information to the Soviets -- the names of two KGB officers who may have been defectors -- in return for $50,000.

SUMMER 1985: Ames turns over to the KGB what he calls "the keys to the kingdom," the names of all KGB agents that he knew of who had worked for the United States, and starts depositing large sums of money in Northern Virginia bank accounts.

AUGUST 1985: Ames divorces his first wife and marries Rosario Casas.

SEPTEMBER 1985: Ames gets a note from the Soviets saying they have set aside $2 million for him. He begins collecting it in small amounts of cash.

1986: The CIA transfers Ames to Rome. He steps up his work for the Soviets and opens a Swiss bank account as part of an effort to conceal his illegal income.

1987: A CIA damage assessment after the defection of former CIA operative Edward Lee Howard shows that the losses of some agents cannot be attributed to Howard. The CIA launches a secret internal investigation to find a leak at the agency.

1989: The Soviets write Ames a "Dear Friend" letter in which they give him a financial accounting and promise him a country home. The accounting states that more than $2.7 million has been appropriated for him. Ames returns to the United States with an assignment at CIA's headquarters at Langley. He and his wife pay $540,000 for a house in Arlington and spend lavishly on improvements.

1991: In a routine background investigation, a CIA polygrapher asks Ames about any outside financial activities and gets a reaction on his machine. Ames covers it by saying that he is thinking about retiring and going into the import-export business. The FBI and CIA begin a joint investigation in search of a mole and Ames is one of numerous suspects.

1992: Rosario Ames first learns of her husband's espionage after finding a note about a meeting with the Russians in his wallet. She begins to aid and encourage him.

MAY 1993: Based on new information, reportedly from a defector, the FBI begins a criminal investigation of Ames.

SEPTEMBER 1993: Agents watch as Ames and his wife drive to Northwest Washington in search of a signal from the Russians.

OCTOBER 1993: Ames leaves a chalk mark on a mailbox -- code name "Smile" -- at 37th and R streets NW, signaling his intent to meet with the Russians later that month in Colombia. During the meeting, the Russians promise Ames an additional $1.9 million.

FEB. 21, 1994: The FBI, fearing Ames is about to flee the country, arrests him a few blocks from his home; agents arrest Rosario Ames at the residence. She tells agents that her husband was a double agent for Moscow.

APRIL 28, 1994: Ames and his wife plead guilty to charges of conspiracy to commit espionage and conspiracy to evade taxes.