Over the last 15 years, the US ballistic missile defense system (US BMDS) has developed into a cornerstone of US alliance policies in the Asia-Pacific. However, given the long-term budgetary horizon and fiscal constraints resulting from sequestration, the Department of Defense was tasked to conduct a comprehensive review of US missile defense programs and capabilities, in an effort to develop a more cost-effective and sustainable ballistic missile defense strategy.

This study aims to contribute to the DoD’s review with particular focus on the challenges, opportunities, and recommendations for the Asia-Pacific theater. In specific the study is geared to answer four distinct questions:

(1) What are the strategic and tactical objectives of the US BMDS in the Asia-Pacific?

(2) How does BMDS fit into the Integrated Air and Missile Defense (IAMD) 2020 vision?

(3) What role can regional US allies play in the context of IAMD?

(4) How will IAMD influence the strategic balance in the Asia-Pacific?

The study is organized into three chapters, each with its own policy recommendations. Chapter one sets the overall context for ballistic missile defense (BMD) in the Asia-Pacific by synthesizing the BMD capabilities of Japan, South Korea, Taiwan, and Australia, with a specific focus on the tactical objectives of forward-based US BMD elements. Chapter two assesses the strategic goals of the US BMDS in the Asia-Pacific, in relation to: (1) alliance reassurance, (2) strategic and regional stability, (3) deterrence, and (4) left- and right-of-launch missile defense options. Chapter three shifts to the concept of IAMD by focusing on defensive counter-air operations that are not part of the BMD threat portfolio, such as cruise missile defense (CMD), counter-unmanned aerial systems (CUAS), and counter-rockets, artillery, and mortar (C-RAM). The study concludes with final thoughts and summarizes answers to the four overarching questions.