By refusing to sign the new UN Nuclear Weapons Prohibition Treaty, Japan has put itself on the wrong side of history, geography, legality, morality, and humanity. The treaty is part of the broad historically progressive trend since 1945 to limit and abolish nuclear weapons and their use. The normative architecture includes the Non-proliferation Treaty (NPT), the Comprehensive Test Ban Treaty, the Nuclear Suppliers Group, regional nuclear weapon-free zones, the Proliferation Security Initiative, and the International Atomic Energy Agency. Geographically, global nuclear risks and threats exist in especially acute form in the Asia-Pacific and most states of the region voted solidly for the ban treaty. The NPTâ€™s legal obligation to eliminate nuclear weapons was strengthened by the World Courtâ€™s Advisory Opinion in 1996. Most countries and peoples of the world overwhelmingly abhor the bomb as deeply immoral. The ban treaty expresses their collective moral revulsion and is rooted in humanitarian principles.