In the United States a highly politicised debate has blown up between the Clinton administration and its republican opponents as to the merits of the Comprehensive Test Ban Treaty (CTBT).

Several specific countries must both sign and ratify the agreement before it can enter into force - among them the United States, Russia, China, India, Israel and Pakistan.

Both India and Pakistan have so far refused to agree to the deal which seeks to halt all nuclear wepaons testing.

But President Clinton's impassioned plea to the Republican-controlled Senate to ratify the document seems to have fallen on deaf ears.

Democrats back the treaty and most Republicans oppose it. The fact that the US presidential campaign is already under way has not helped matters.

But as much as partisan politics, this debate reflects very different views about arms control.

To its supporters the CTBT represents the corner-stone of efforts to reduce the dangers of the spread of nuclear weapons.

Computer simulation

Such a treaty, it is argued, would effectively freeze membership of the nuclear weapons club and prevent existing nuclear weapons states from developing ever more sophisticated bombs.

Arms control advocates believe that the United States could safeguard its own nuclear arsenal without further testing, using computer simulation.

But the test ban's critics say that its goal of zero nuclear test explosions cannot be verified.

They argue that it is an agreement that would constrain the United States while allowing rogue governments to continue weapons development.

And they argue that testing is necessary to maintain stock-pile safety.

Many experts believe though that this test ban treaty is better than nothing. The New York Times decribes it as "imperfect but necessary".