The third nuclear test conducted by the Democratic People's Republic of Korea created greater "shock waves" than the second. That is because many nuclear experts suspect the DPRK might have tested a bomb small enough to fit on Unha-3, the carrier rocket it launched in December to successfully put a satellite into obit.

Some countries, especially the United States, the Republic of Korea and Japan, fear that the DPRK would soon be able to fit nuclear weapons on missiles and threaten their security. Indeed, the DPRK has threatened to launch "pre-emptive" nuclear strikes against the US, the ROK and Japan.

In the face of the DPRK's nuclear threats, many people (politicians included) in the ROK and Japan feel the need to strike a "balance of terror" by developing their own nuclear weapons. Seoul and Tokyo may face great hurdles to develop nuclear arms, but the very fact that they have felt the need for it is worrying, because it could trigger a nuclear arms race in the region.