Terrorism is now posing a new threat to international security. After the 9-11 disaster in America, the Japanese government immediately established 'Anti-terrorism special measure bill' to back up the American anti-terrorism wars. This special bill not only set up a cooperative mechanism of crisis management, but added new elements to the Japanese Defense Policy as well.This paper deals with three main issues. The first issue is why Japanese government is capable of enacting and passing this special bill so promptly, and next, why 'the bill' is urgent since the overseas military activities by Japanese Self Defense Forces are under law. The last issue will discuss the arguments arising from this special bill.