Opposing any form of clemency were many active and retired U.S. officials, including Donald Rumsfeld, Dick Cheney, former CIA director George Tenet; several former U.S. Secretaries of Defense; a bi-partisan group of U.S. congressional leaders; and members of the U.S. intelligence community. They maintained that the damage to U.S. national security due to Pollard's espionage was far more severe, wide-ranging, and enduring than publicly acknowledged. Though Pollard argued that he only supplied Israel with information critical to its security, opponents stated that he had no way of knowing what the Israelis had received through legitimate exchanges, and that much of the data he compromised had nothing to do with Israeli security. Pollard revealed aspects of the U.S. intelligence gathering process, its "sources and methods". He sold numerous closely guarded state secrets, including the National Security Agency's ten-volume manual on how the U.S. gathers its signal intelligence, and disclosed the names of thousands of people who had cooperated with U.S. intelligence agencies.