Going down a bomb

All weekend there have been mass demonstrations in - of all places - Tahiti. Tahitians are outraged at President Jacques Chirac's decision to resume the testing of a new generation of nuclear weapons in the Pacific ocean. The tests are due to take place between September and next May and Greenpeace has pledged to do its best to stop them. And this time, they're right. On both environmental and political grounds they deserve our support.

The environmental argument isn't about the probable levels of radioactive fall-out in Tahiti, which is 600 miles away, still less in more distant New Zealand or Australia. These will be underground, not atmospheric tests, and so there should not be very wide surface radiation. Outside the exclusion zone it will be difficult even to hear the explosions, let alone see a Nagasaki-style mushroom cloud.

Rather, the point is that such tests are risky, and they're unnecessary. Things can go wrong even in "controlled" explosions, and - for all the public knows - may well have done so in any of the 187 explosions the French have conducted at Mururoa. France insists the tests are entirely safe. If that were certain, there would be no reason to conduct them in a remote part of the Pacific: they might as well be done in laboratories in Paris or Lyons - or under Clermont-Ferrand.

But the most important issues at stake are military and political. After all, what good reason is there for testing new nuclear weapons systems at all? France already possesses a nuclear arsenal that ought to serve its legitimate defensive purposes, now that the Cold War is over. In 1992 President Francois Mitterrand committed France to a moratorium on nuclear testing. Earlier this year a new test ban treaty was signed and is due to come into force in 1996. The 1968 non-proliferation treaty has also just been indefinitely renewed.

With these tests, France is signalling to the world that its conception of international relations in the 21st century is one of nuclear deterrence. It is surely not merely a coincidence that the United States has announced that it may also soon restart nuclear tests. Nothing could be more dangerous at a time when there are scores of nations in Africa and Asia dreaming of settling their quarrels with their neighbours by rattling missiles.

For all these reasons, when the skipper of the Rainbow Warrior II navigates his craft into the exclusion zone some time towards the end of this week, the world should be supporting him loudly. If international diplomatic and journalistic condemnation, the voices of the protesters in Tahiti and the boycotts of French goods by Australian consumers are not enough, we should hope that the physical courage of Greenpeace activists will succeed in changing Mr Chirac's mind just as they changed the mind of the board of Shell UK.