Plan Zero was a mysterious operation created in the years of the Cold War by the Dark Council member Darth Baras. It was created at the directive of Darth Vengean though it was Baras who was responsible for taking it forward and had spent a decade in developing it in secret. This was an elegant strategy that aimed at eliminating the Republic Military's leadership as part of a strike that would restart open warfare with the Galactic Republic.
As a result, Baras had not wielded his full strength in the power plays in the Sith Empire. Instead, he sought to strike not against the heroes of the Republic but rather at those behind the scenes and led to the Sith Lord capturing SIS agents in the Outer Rim and courting greedy Senators through his proxies.
Vast resources had been spent in bringing together information on the greatest and most elusive generals of the Republic. The careful development of this operation meant that no Sith was allowed to interfere with Plan Zero and no spy of the Republic was allowed to discover it in the fear that they would eventually warn the intended targets.
In the Cold War era, Darth Baras's Sith apprentice was charged with eliminating each of the great Republic leaders until open war was declared by which point it was expected that victory was assured as a result of the actions of Plan Zero.
- Star Wars: The Old Republic (First appearance)