Treason. Such an ugly word. Aldrich Ames prefers "spying." Such rationalizations are a part of what made Ames one of the most cold-blooded traitors in U.S. history. He also remains the most damaging mole (to our knowledge) to betray the CIA.

Childhood and Early Career
Spying was in Ames' blood. His father was a spy, and he spent summers working for the agency (nothing devious of course; he was only 16 and simply helped prepare resources, such as fake money for training exercises.) With the help of his father, he was later hired by the agency and began training to become a case officer in the Directorate of Operations, the CIA's covert branch. His early career proved to be lackluster. He seemed to have difficulty recruiting spies.

He eventually caught a few breaks managing already-turned "assets" (as spies are referred to) and began to make some progress. He was, however, consistently passed over for promotions, due to his lack of recruiting abilities. His personal life was a mess and his marriage was falling apart. He began drinking heavily. In order to prove his worth, he took a tour in Mexico City where he once again failed to recruit a single spy. Distraught, his failure in Mexico City only led to more drinking and disillusionment. His agency friends were worried about him, and set him up with Maria del Rosario, a cultural attaché for the Colombian Embassy in Mexico. Ames promptly fell in love.

Thanks to an agency friend who only knew of Ames' success with managing assets, Ames was finally promoted, and moved back to Washington D.C.. He was named counterintelligence branch chief in Soviet operations, a job that would give him access to nearly all of the agency's Soviet cases. Eventually, Rosario came to join him, and he divorced his first wife and remarried.

At the time, the CIA was enjoying an extensive network of intelligence assets, penetrating every aspect of the Soviet system. The range and degree of programs was wider than it had ever been, and Ames had access to all of it. Meanwhile, Rosario was running up huge bills that Ames simply couldn't afford to pay. She talked with her mother on the telephone every day, running up enormous long-distance phone bills. The phone bills along with other gratuitous spending and the cost of his divorce put Ames in deep debt.

Betrayal and the Slippery Slope
When and how Ames exactly began his espionage for the Soviet Union is still debated. Ames claims that he had come up with the "perfect scam." In exchange for $50,000 (roughly the amount of debt he had run up), he would give the Soviets the names of three Russians spying for the CIA. However, the three agents he claims he gave up were actually "double agents" who still worked for the KGB. This was a rather elegant proposal: he was able to shield the U.S. and the CIA from harm because he was only giving the KGB the names of its own agents.

The FBI and CIA disagree, however. They claim Ames gave up the CIA agents who were most likely to discover Ames' betrayal.

Regardless of how malicious he was when he started, this act represented the first step down a slippery slope. Two days after Ames had received his first payment from the Soviets, the infamous Walker spy ring was broken up and arrested for betraying Naval secrets to the Soviets (and not long after that, another Soviet spy, Ronald Pelton, was arrested for giving away, among other things, the cable tapping operation known as Operation Ivy Bells.) The timing of Walker's arrest was suspicious and Ames became scared.
"I knew how well we had the Soviet system penetrated. It was only a matter of time before one of our spies learned what I had done. I was very vulnerable."
Ames immediately moved to protect himself. He met with his Soviet handlers and gave them the name of all of the CIA's "human assets" that he knew (with the exception of one friend whom he did not want to betray, but later did - on 2 occasions!) along with several pounds of CIA intelligence reports (apparently, he simply whisked them out of the CIA's office in his briefcase.) The Soviet Politburo, severely embarrassed by the CIA's success in recruiting spies, ordered a mass arrest, executing many of the spies that Ames sold out.

On the Trail of a Traitor
Naturally, the CIA noticed that their spies were disappearing and ordered an investigation. The CIA was still reeling from the paralyzing effects of a career-destroying mole-hunt led by the paranoid James Jesus Angleton a few years earlier, so the investigation did not focus on trying to find a mole, preferring instead to explore other logical explanations. CIA investigators mistakenly concluded that the "1985 losses" (as they became known) were unrelated. Some were thought to have been caused by a defecting agent, others by mistakes made by the spies themselves. This was apparently not convincing, however, and several hard-nosed agents pressed for further investigation.

One of the CIA officers assigned to the case had a background in accounting and had the brilliantly obvious insight that the best way to find a mole was to find unexplained wealth among your own agents (such a tact may have helped nail Pelton, who sold out Ivy Bells for $35,000 to pay off his debts, and maybe even Walker too.)

All during this time, Ames was working for the Soviets and getting paid rather handsomely. He made no attempts to hide his newfound wealth, nor did his free-spending wife. Expensive wardrobe, a Jaguar sports car, Rolex watches, and so on. Most assumed that Rosario came from a wealthy family (some rather sloppy investigation confirmed that, though it turns out that though the family was socially prominent, it was still poor), but one agent who knew her and Ames from Mexico City knew that wasn't true, and reported it.

That proved to be Ames' undoing. He and his wife's overspending were a vital clue, though it didn't actually prove anything. One investigator noticed, however, that Ames had made several suspicious bank deposits in 1985. These deposits happened to coincide with the days that he had lunch with his Soviet handler (whom everyone thought Ames was trying to develop as an "asset.") Ames had taken few precautions to hide his payments, and it was easy to build a case from there.

Denouement
On February 21, 1994, Ames and his wife were arrested by the FBI. Investigators had found several damning pieces of evidence, including letters to and from his Soviet handlers, and further evidence of he and his wife's gluttony. She was sentenced to 5 years in prison, then deported back to Colombia. He was sentenced to life in prison. He jokes that, ironically, he sealed his own fate: The KGB had no one to swap for him. It had killed all of the spies it had arrested who were worth trading.
Ames would later attempt to rationalize his treason. "A lot of the barriers that should have stopped me from betraying my country were gone," he said. "The first barrier was the idea that political intelligence matters. It doesn't." Ames said he had become disillusioned because several presidents, beginning with Richard Nixon, had ignored the CIA's findings because they did not suit the White House's political agenda. "I realized these men's actions do not excuse mine, but they did influence my decision making and help grease the slope...I also had come to believe that the CIA was morally corrupt. The CIA is all about maintaining and expanding American imperial power, which I had come to think was wrong... and finally, I did not feel any sense of loyalty to what mass culture had become. How does treason fit into all of this? In some ways, not at all. I would love to say that I did what I did out of some moral outrage over our country's acts of imperialism or a political statement or out of anger toward the CIA or even a love of the Soviet Union. But the sad truth is that I did what I did because of the money and I can't get away from that. I wanted a future. I wanted what I saw (Rosario and I) could have together. Taking the money was essential to the recreation of myself and the continuous of us as a couple."

Sources and Further Reading
My main source:
http://www.crimelibrary.com/terrorists_spies/spies/ames/1.html?sect=23

An Assessment of the Aldrich H. Ames Espionage Case and Its Implications for U.S. Intelligence
http://www.fas.org/irp/congress/1994_rpt/ssci_ames.htm

A Letter from Aldrich Ames on Polygraph Testing
http://www.fas.org/sgp/othergov/polygraph/ames.html

This is an edited version of an article on my website:
http://kaedrin.com/weblog/archive/000778.html