Freedom of speech is a cornerstone of American democracy, but even that has its limits. If a U.S. military or intelligence officer finds damaging information in a classified document, is it their duty to report it, or is revealing a government secret still an act of treason?
Throughout American history, there have been individuals who felt compelled to leak classified information about military and government operations.
“Some are facing a crisis of conscience—they feel they can't be associated with American policy anymore,” says Kateen Mistry, historian and co-editor of Whistleblowing Nation: The History of National Security Disclosures and the Cult of Secrecy. “For others, it's more about trying to improve the system. They want to enhance the functioning of the state.”
Here are five of the biggest military intelligence leaks in U.S. history starting with an episode that helped spark the Revolutionary War.