Non-aggression pact of 3975

The non-aggression pact of 3975 was signed and allowed for at least twenty-five years of peace. (TV: "The Nightmare Begins")

Prior to its signing, the Space Security Service was involved in a conflict with the Sontarans. Travelling from the future, Sara Kingdom told Captain Daphne Papas that soon there would be peace "for a time". (AUDIO: The Sontarans)

In 4000, Guardian of the Solar System Mavic Chen spoke of the continued peace and prosperity the pact continued to offer to the galaxy as it entered a new millennium. However, he was secretly part of an alliance led by the Daleks seeking to invade the solar system. (TV: The Daleks' Master Plan) When Earth discovered this plot, (PROSE: The Mutation of Time) the Great War against the Daleks began. (PROSE: The Evil of the Daleks)