Source: National Bureau of Asian Research

This chapter examines the future of Japan’s hedged dependence on U.S. extended deterrence and encourages more imaginative thinking about potential outcomes and strategic implications as the second nuclear age unfolds.

Main Argument

• With the U.S. nuclear umbrella shrinking and nuclear threats in Asia becoming greater and more complex, analysts cannot dismiss a nuclear-armed Japan as a purely academic exercise.
   
• While we do not expect a Japanese nuclear breakout in the near term, Washington’s traditional reassurances—massive numbers of weapons deployed in theater and a robust regional presence—have given way to a less convincing reliance on specific weapon systems amid a diminishing conventional military advantage.
   
• Enhanced bilateral dialogue has been used to strengthen the alliance, but Japan’s neighborhood is more dangerous than ever, and the many domestic constraints on Japanese nuclear breakout—cultural, political, and institutional—could become less restrictive than before.
  

Policy Implications

• A U.S. decision to sustain extended deterrence will require significantly more resources and attention than heretofore assigned.
   
• A more integrated, alliance-based approach to deterrence might therefore become attractive.
   
• Alternatives to Japan’s long-practiced nuclear hedge may come to have appeal in Tokyo or Washington.
   
• Coordinated regional action to limit North Korea’s nuclear development remains critical.

Read the full chapter here.

This chapter is from Strategic Asia 2013-14: Asia in the Second Nuclear Age. Read more about Strategic Asia, including information on how to order the complete book, here.