The document provides an overview of Aldrich Hazen Ames, a former CIA operations officer who engaged in espionage from 1967 to 1994. His actions resulted in the deaths of at least 10 CIA assets and the shutdown of CIA activities in Russia. As a CIA officer, Ames betrayed the identities of CIA officers and high-ranking assets to the Soviet Union and Russia. This compromised CIA operations and led to the deaths of valuable sources during the Cold War. Ames' espionage was considered some of the most damaging to US intelligence gathering during that era.