Blast from the past: the nuclear test ban treaty

by Morgan.J / 13 July, 2012
Half a century after a bomb blast 400km above Johnston Atoll, the nuclear test ban treaty has still not taken effect.


Fifty years ago this month, many Aucklanders witnessed an aurora, a spectacular display of lights caused by the interactions between charged particles and atoms in the Earth’s atmosphere. The New Zealand Herald described the aurora as an intense glow above the northern horizon that spread rapidly across the sky before “the luminous red band widened, and quivering white shafts of light could be seen within it”. Auroras are usually confined to much higher latitudes, but there was nothing usual about this aurora. On July 9, 1962, the United States had launched a 1.2-megaton hydrogen bomb on a rocket and exploded it 400km above Johnston Atoll, thousands of kilometres from New Zealand, in the North Pacific Ocean.

The high-altitude explosion, designed to test the effect of a nuclear detonation on radio and radar communication, caused an electromagnetic pulse that led to power cuts in Hawaii and disrupted telecommunications systems throughout the Pacific. The Herald editorial described the eerie glow from the nuclear explosion as doing “more than a hundred protest marches to fill men’s minds with dread”.

Prime Minister David Lange later recalled that “the confusion in the sky that night haunted me as a vision of a man-made apocalypse, a terrifying retaliation of natural forces against the evil of unnatural invasion and a warning that a small country at the edge of the world in the South Pacific was no longer far enough away from the quarrels of the great powers to escape their consequences. It was a shock to realise that the power of nuclear weapons could straddle the world and unleash a threat on an inoffensive country like New Zealand.” The July 1962 detonation was one of a series of American nuclear tests that created mixed feelings in New Zealand. The UK’s last Pacific nuclear test had been in 1958 at Christmas Island, after which the three nuclear powers had agreed to a temporary moratorium. France was not to start its Moruroa nuclear tests for another four years. The Johnston Atoll nuclear test was frightening, but the US was still an ally and the leader in the West’s fight against communism; the ostentatious tests were a response to the USSR’s own recent resumption of nuclear testing.

Although the Herald acknowledged that the “yearning to see these dreadful engines of destruction abolished must be nearly universal”, it also stated that to “clamour for immediate nuclear disarmament flies in the face of reality”. Later that year, the NZ Atomic Energy Committee, an advisory committee established in 1959, responded to a request from the Prime Minister’s Department by commenting on the potential impact of high-altitude nuclear tests on the ionosphere. It advised that these tests would increase the levels of long-lived radioisotopes such as strontium-90, and recommended that the New Zealand Government “oppose further high-altitude tests unless such tests have the support of, and the scientific observations are co-ordinated by, an internationally recognised scientific organisation”.

This, of course, never happened. It was only a few years later that New Zealand began making regular diplomatic protests in response to France’s Pacific atmospheric nuclear tests. Then, in June 1973, Prime Minister Norman Kirk sent the Navy frigate HMNZS Otago to Moruroa to protest against French nuclear testing. France continued atmospheric nuclear tests at Moruroa Atoll until 1974, and conducted underground nuclear tests there until 1996. Today, the Comprehensive Nuclear Test-Ban Treaty, adopted by the United Nations in 1996, bans all nuclear explosions in all environments. The treaty has not yet entered into force, though, and the most recent nuclear tests were by India and Pakistan in 1998 and North Korea in 2009.

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