Author: Ken Jimbo, Keio University

The sinking of the Cheonan and shelling of Yeonpyeong Island in 2010 raised concerns for both the South Korean and US governments that North Korea may no longer be conventionally deterred.

The two governments have been reviewing how their basic and extended deterrence policies should be reorganised to adapt to this new dimension in North Korea’s behaviour. Read more…

Author: Ken Jimbo, Keio University

Although much remains murky regarding the technical details, North Korea’s second nuclear test on May 25 was considerably bigger and far more sophisticated than the previous one.

Up until this year, few attempted to define North Korea as a Nuclear Weapon State: however, much-increased yield of North Korea’s recent nuclear detonation (10–20 kilotons) compared with the 2006 test has convinced many observers that North Koreans have not only improved the precision of their implosion technology but have overcome a major technical hurdle to miniaturizing its nuclear device. Analyses suggest that North Korea’s nuclear capability is at least on the brink of the operational deployment stage, if not indeed there already.

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