Japan is trying to speed up the installation of an anti-missile system, for defense against possible attack by North Korea. The Japanese system is using U.S. Patriot Pac-3 missiles initially, and Aegis SM-3 missiles by 2007. The Patriot systems will go online this year, rather than next. Japan is very nervous about what is going on in North Korea, and fears a breakdown in the government and possible military activity (against Japan).
