On June 8, 1987, the parliament of New Zealand passed a law that has become a milestone in the evolution of the nation. The primary purpose of the New Zealand Nuclear Free Zone, Disarmament, and Arms Control Act 1987 was to establish a nuclear- free zone in New Zealand. Any New Zealand citizen or resident is forbidden to manufacture, acquire, possess or have any control over any nuclear or biological weapon.

The law covers all New Zealand territory, including airspace and ocean territory up to the 12 nautical mile limit. The entry of nuclear-powered ships and the dumping of radioactive wastes are prohibited. The law also established a Public Advisory Committee on Disarmament and Arms Control. I was a member of PACDAC as a professor at the University of Otago in the early 1990s.

Against the global backdrop of elevated nuclear threat levels, many New Zealanders concluded that involvement in the United States' nuclear-deployment practices exposed the country to global nuclear risks more than it protected the country against nonexistent national security threats. NGO activists succeeded in converting the Labour Party to their cause and in 1985 the Labour government of Prime Minister David Lange terminated the practice of permitting the entry of nuclear-capable U.S. ships into New Zealand ports without an explicit declaration that they did not carry nuclear weapons. Because that was a global U.S. policy, Washington refused to make an exception for a minor ally and New Zealand effectively parted company from the ANZUS alliance, which fractured into two bilateral alliances between the U.S. and Australia, and New Zealand and Australia.