The Spock Defense was a tactic developed by Spock as a means of combating the threat posed by the Totality which was using its powers to stop warp travel throughout the galaxy.
The plan involved vessels increasing their gravity which partially slowed the process of tampering by the Totality. Those remaining Starfleet vessels that had critical crew required to combat the Totality in some way were also transferred to the few warp drive ships present. After its creation, the news of the Spock Defense was later transmitted to the Klingon Empire and the Romulan Star Empire. (TOS novel: Captain's Glory)