Missiles in Japan

I read this article about the US deploying interceptor missiles in Japanhere. iTs interesting because even though they're interceptor missiles they supposedly can't reach the kind of long range missile that the North Koreans are causing all of these problems over. Also, an official supposedly told a delegation of South Korean visitors to the North that there was no reason that his country would start a war and that they were arming to prevent such a war from occuring.