I will trace the early history of the Southern Korean Workers' Party and examine how the rise of the SKWP ensured the coming of a twilight for "Unitary Socialism" and led to the death of any possibility for non-ideological unification prior to the outbreak of the Korean War. I will show that the two events under examination were simultaneously linked with each other that the former not only determinied the latter but also ensured a synonymous relationship between the Southern Left and the party, thereby laying the cornerstone for Communist supremacy in southern Korea. This would serve as the groundwork for the Left-Right clash in southern Korea that would last from 1946-1948 and inspire north Korea to make the ultimate decision to launch war on June 25, 1950.