Here's the review for Breach...

In December 2000, the FBI paid a Russian agent $7 million for the KGB's file on an American mole - known to the KGB at the time only as Ramon Garcia. The file included a note of the mole about "purple-pissing Japanese" and Robert Hanssen, who was fond of the saying, became the prime suspect in the investigation. 

In February, 2001, the FBI arrested the 25 year veteran, considered the "the worst spy in history" with a career as a double agent that is estimated to have cost countless lives and secrets, and which to this day, the full extent of the damage, is not entirely known. Based on fact, Breach picks up in the last two months of the investigation against Hanssen, when rookie and wannabe Special Agent, Eric O’Neill (Ryan Phillipe), a computer specialist bucking for promotion, is appointed as Hanssen’s clerk in a division set up purely trap the master spy. The FBI had to catch him red-handed, because all the evidence they had on him (in the Russian file) was inadmissible in court.

Recruited for the job by FBI Special Agent, Kate Burroughs (Laura Linney), O'Neill is initially told only that the sting is an investigation of Hanssen's sexual habits. He is soon drawn in by the devout Catholic’s knowledge and experience. Hanssen, a member of the strict Opus Dei cult, starts to ingratiate himself and his family into Eric’s life, as well, causing a great deal of strain between him and his lapsed-protestant East German wife.

Chris Cooper is elegantly creepy as Hanssen, the man whose wife (Kathleen Quinlan as Bonnie Hanssen) prays on her knees before bedtime, where her husband secretly films her having sex and trades the films on the internet. Phillipe is particularly good as the idealistic O’Neill. His journey through the film, from complete faith the direction his life is headed, to questioning everything he believes, is fascinating to watch. As he grapples with his feeling for a man he can’t seem to decide whether to admire or despise, O’Neill is forced to make choices he finds difficult, even repellent, all the while trying to keep his cool and not give the game away. Equally convincing is Linney, jaded and alone, who seems weighed down by the knowledge that one of the Agency’s best and brightest has turned out to be a traitor.

This is a taut, intriguing thriller, made all the more frightening by the fact that it actually happened. Written and directed by Billy Ray (Flightplan, Shattered Glass), the tension builds gradually, but relentlessly, and it's only knowing that they did actually catch Hanssen that stops you chewing your fingernails down to the bone.