| ® | The Unheeded Warning | 193 an adversary’s intelligence organization that it could not mount any of its own surprise cyber attacks. It would also make it difficult if not impossible for adversary services to recruit a spy in the NSA. For example, the CIA penetration of the SVR in 2010 prevented it from using its sleeper network against U.S. targets. “The best defense in this game may be an overwhelming offensive,” a former intel- ligence official said to me. “But that strategy only works if we can keep secret sensitive sources.” Central to this offensive strategy was the NSA’s National Threat Operations Center in Oahu. It employed threat analysts to surrep- titiously monitor the secret activities of potential enemies, mainly China, Russia, and North Korea. A large part of their job was to make transparent to the United States the hostile activities of the Russian and Chinese services so that they posed little if any intel- ligence threat to America. This strategy worked so long as the NSA guarded itself, but it also raised the issue, as the Roman Juvenal famously warned, “Quis custodiet ipsos custodes?” (Who will guard the guards themselves?) © Less than three years after the NSA had received the Poteyev re) warning, instead of guarding secrets, Snowden stole them. Despite all the measures the NSA had taken to protect its vital secrets, a lowly civilian employee had walked away with the lists of secret NSA sources in China and Russia and then gone first to China and then to Russia. In the hands of their intelligence services, these stolen lists had the potential to totally upend the NSA’s offensive strategy. Because Russia and China have an intelligence treaty for sharing such spoils between them when it is to their mutual advantage, it had to be assumed that if either country had acquired the secrets from Snowden, they would be shared between them, altering the balance of power between the communications intelligence services of the United States a