This paper provides an overview of the Nautilus Institute’s exploration of two inter-linked but highly contested aspects of the strategic nuclear situation on the Korean peninsula: the complexity and uncertainty associated with United States assurances of nuclear extended deterrence to South Korea (and Japan), and the potential contribution a nuclear weapon free zone to shifting the current impasse concerning North Korean nuclear weapons. The theoretical inquiry in to the current state of nuclear extended deterrence is followed by an examination of the necessity, viability and desirability of reformed versions of nuclear extended deterrence (such as collective deterrence), and of three conceivable generic alternatives to reliance upon nuclear extended deterrence: namely nuclear rejection, nuclear recession, and conventional deterrence (possibly combined with existential deterrence). A bilateral nuclear weapon free zone, with the door held open to North Korea to join at a later stage, would act as a circuit-breaker in the stalemated nuclear confrontation; prefigure a United States negative security guarantee to North Korea in a future rapprochement; and reduce ongoing regional anxieties by locking both South Korea and Japan into a legally binding non-nuclear security posture.