American officials are quietly and delicately alerting intelligence services around the world that Edward Snowden made off with documents that could out them as US collaborators, government sources tell the Washington Post. Countries around the world—some of which are not officially US allies—have been helping the US gather information, particularly on geopolitical foes like Iran, Russia, and China. These partners play no role in the NSA surveillance Snowden has revealed so far; rather, they're helping with more traditional espionage, primarily concerning foreign military capabilities.
One NATO ally, for example, has been passing information on Russia to the US Navy and Air Force. "If the Russians knew about it, it wouldn't be hard for them to take appropriate measures to stop it," an official said. The US also has to tread lightly in warning these partners, because some parts of the respective country's government may be unaware of the secret alliance. Of course, Snowden has vowed not to publish anything that would harm national security, but officials worry that hackers could obtain the documents. (Yesterday's big reveal via Snowden: The NSA got its hands on the phone numbers of 35 world leaders.)