Operation Olympus was a Starfleet battle plan in an alternate reality where Spock died during his childhood and the United Federation of Planets was at war with the Klingon Empire, the latter believing that the Federation would threaten them with Genesis Device superweapons.
The plan was proposed by Starfleet and supported by the Federation Council. It involved a push towards the Klingon homeworld of Qo'noS and using a small Genesis weapon on its moon of Praxis, thus showing the Federation's position of power to the High Council of the Klingon Empire. In order to facilitate the plan, the Operation required the use of the technical expertise of David Marcus, but after he realized the military aims of the plan he decided to withdraw his support from it. (TOS novel: The Chimes at Midnight)