As much as the press tries to bulk up public confidence in the Obama administration, it is doubtful Hillary Clinton's trip to Japan will have any effect on North Korea.
First of all, North Korea is a patrilineal dictatorship run one of the most morally corrupt people on the planet. Famines wipe out the North Korean populace while Kim Jong-Il and his military attaches eat well. Indeed, one of the chief complaints of North Korean refugees is dental problems, their teeth having fallen out due to malnutrition. Psychological problems are also a concern. Their cousins to the south should be attentive to these health problems as they may one day have to deal with them on a grand scale.
Secondly, North Korea has never adhered to any treaty, promise or law. Clinton's anger over North Korea's launching of missiles falls flat. Of course it is illegal to fire missiles. That has not stopped it before.
Third, North Korea rattles its sabre when it wants something and gives nothing in return. Any aid given to it by South Korea, the US, Japan or even China ends up in the hands of a rag-tag military and not where it is needed.
Fourth point, North Korea has yet to admit its full complicity in kidnapping not only Japanese citizens but South Korean citizens, as well. The fate of these people is largely unknown. As no one can enter North Korea and North Korea has no track record of honesty, anything could have happened to them.
Professor Sung-Yoon Lee outlines the problems dealing with North Korea here.
Why Hillary Clinton can even think she can make headway with the North Koreans when the South Koreans have been largely unsuccessful is beyond belief. Why she thinks she can- or should- normalise relations is just morally repugnant. What more can be said about a country that props up a father-son/cult-of-personality regime and where people starve to death?