There’s no doubt North Korea’s recent bellicose actions have Seoul and Tokyo in particular on edge given their proximity to North Korea. As such, South Korea wants to take their relationship with Washington to the next level. As Blaine Harden explains,
As state media in North Korea continue to warn of possible nuclear war, South Korean President Lee Myung-bak flew to Washington for talks with President Barack Obama at which Lee is expected to seek a written promise of continued U.S. nuclear protection. The United States has maintained a nuclear umbrella over South Korea since the Korean War and it periodically reaffirms that protection, although not at the level of a White House statement.
The impact of agreeing to an explicit White House statement guaranteeing nuclear protection has two possible implications. On the one hand, it is simply formalizing seemingly well-known guarantees to help assuage South Korean fears. On the other hand, it arguably represents a shift away from calculated ambiguity as the U.S. officially declares to response with nuclear weapons if necessary. It ups the ante which according to some probably makes it less likely for North Korea to play with fire and according to others probably makes it more likely that a wire gets tripped and a conflict goes hot. It will also be interesting to see should the U.S. be willing to grant White House statement level explicit protection if other countries use that as a reason they should receive protection, whether it be countries in the Middle East seeking to initially gain shelter under the U.S. umbrella or other countries currently under the umbrella try to take the relationship to the explicit stage.