On 18 December 2020, the Japanese Cabinet decided on a new policy to upgrade its missile defence systems to cope with the evolving missile threats in the surrounding region. Meanwhile, speculations have been brewing with regard to whether Japan might abandon its traditional policy of exclusive self-defence, drift from its alliance with the United States or start developing indigenous strike capabilities against military targets within its adversaries’ territories.

This report provides an overview of Japan’s efforts to upgrade its missile defence systems to meet with the evolving security environment, and the debates surrounding such efforts within Japan. The report also analyses the key factors shaping the future course of Japan’s missile defence strategy.