General order 24
From FEInfobase
Starfleet General Order 24 lays out new protocols allowing Starfleet vessels to use their weapons against inhabited terrestrial cities. The order's full text is classified for Command-level access only, but it is known that it authorizes planetary bombardment only in situations of extreme threat to the security and safety of the Federation, and only after the Starfleet vessel in question has been in orbit actively seeking other solutions for at least 24 hours.