"In the past, lack of policy coordination gave North Korea a kind of leverage," he says. The agreement on a "joint vision," he goes on, sends "a strong message to North Korea" that it cannot drive a wedge between the United States and South Korea.
A de facto nuclear state?
For South Koreans, a key question is whether tough words will translate into action – or incidents reminiscent of bloody clashes in the Yellow Sea in June 1999 and June 2002.
Yet another question is whether North Korea now ranks as a de facto nuclear state regardless of US reluctance to give it such recognition.
The affirmation of US nuclear support for South Korea in the event of a showdown with the North "has the risk of being portrayed as an indirect acknowledgement that North Korea has nuclear arms," says Kim Seung-joo, political scientist at Seoul's Sungkyungkwan University. "The more the allies step up their defense language," says Mr. Kim, as quoted by South Korea's Yonhap news agency, "the easier it is for North Korea to support its claim as a nuclear weapons state."