In the jargon of the CIA, the Budapest Rules are the operational guidelines that permit covert operations to destabilize unfriendly regimes as long as no explicit assurance of active U.S. support is given to opposition groups.

The term derives from the short-lived 1956 anti-communist uprising in Hungary, which was encouraged by the Eisenhower Administration, but was ruthlessly crushed by the Soviet Union after Eisenhower pointedly announced that the U.S. wouldn't interfere.

Many consider this to be a very cynical U.S. policy -- encouraging people to rise up against their government, but withholding US support -- even after the shit hits the fan. The Budapest Rules generally require plausible deniability.