The latest attempt to halt the spread of nuclear weapons, the Comprehensive
Test Ban Treaty, lies dead on the floor of the US Senate. The CTBT, created back
in 1996 to stop nuclear weapons proliferating throughout the world, still needed
to be signed by another 18 countries鈥攊ncluding the US鈥攂efore it came
into force. The US rejection effectively kills the agreement.
Republicans who dominate the Senate claimed the CTBT was dangerous: not only
was it impossible to detect rogue states鈥� clandestine tests, it threatened the
reliability and safety of America鈥檚 nuclear arsenal. Dismayed Democrats and
international observers dismissed the Senate鈥檚 move as reckless party politics.
Thirty-two American Nobel prizewinning scientists attacked the logic of the
decision, claiming that technology no longer required the US to explode weapons
in order to test the reliability of its nuclear arsenal.
The first nuclear weapon, the 鈥淟ittle Boy鈥� that obliterated Hiroshima, was
merely a modified anti-aircraft gun that smashed two chunks of the heavy metal
uranium into each other. When the lumps of metal reached a critical mass, the
atoms began splitting at an ever-increasing rate: a fission chain reaction. But
more sophisticated and powerful bombs require nuclear fusion, the process
whereby the nuclei of lighter atoms, such as hydrogen, stick together. It鈥檚 much
harder to achieve than fission, because there鈥檚 no chain reaction to do all the
work.
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Nevertheless, the US managed it in 1952, when it detonated the first hydrogen
bomb. This redirected the radiation from an atomic bomb 鈥減rimary鈥� onto a flask
full of deuterium (heavy hydrogen) to achieve fusion. At about 10 megatons, this
was some 750 times more powerful than Little Boy.
This hydrogen bomb and its ever more sophisticated descendants have required
extensive testing as part of their development. Thus, the CTBT would
theoretically have prevented nations like India and Pakistan from developing
more powerful and more reliable weapons, and prevented rogue states from
starting modern nuclear programmes. However, opponents of the CTBT say that if
you want to test a weapon for safety (shooting a bullet into it and ensuring
that it doesn鈥檛 blow up) or reliability (letting it sit in a hangar for 30 years
and making sure it will still explode on command), nuclear tests are obviously a
boon.
But the 32 Nobel laureates noted that there were viable alternatives. Among
them is the US Department of Energy鈥檚 Stockpile Stewardship Program, dedicated
to keeping nuclear weapons safe and reliable without the use of nuclear tests.
It has two major tools. The first is hydrodynamic testing, in which engineers
check the plutonium part of the warhead. In the second, confinement fusion
testing, engineers check the hydrogen component of the weapon.
The Stockpile Stewardship Program can鈥檛 test a bomb from the explosion of its
first stage to the ignition of its second stage. But it can verify that a bomb
with a well-understood design is working because all its individual
components are in good order.
鈥淲e understand the weapons very well,鈥� says engineer Frank Von Hippel, of
Princeton University鈥檚 Program on Nuclear Policy Alternatives. This is why he
says that non-nuclear testing is sufficient to ensure that a weapon will perform
as advertised. 鈥淚 think that the Stockpile Stewardship Program is even more than
we need for reliability.鈥� Jon Wolfsthal, of the Carnegie Endowment for
International Peace in Washington DC, agrees. 鈥淭he hawkish view is that our
weapons will not remain reliable and safe, but they misunderstand that stockpile
stewardship is actually working today.鈥�
International observers are also unconvinced by the argument for testing.
Philip Towle, director of the Centre of International Studies at Cambridge
University, says: 鈥淭hey鈥檝e had a very long time to test the reliability of
trigger systems, and there are some states like Israel that are at much greater
risk from nuclear attack who have not needed to carry on testing.鈥�
Another objection by the opponents of the CTBT is the plan鈥檚 supposed
inability to identify violators. 鈥淲ell, this is kind of a distortion of the
evidence,鈥� says Jeffrey Park, a geophysicist at Yale University. 鈥淲e do monitor,
currently, known test sites at fairly low magnitudes鈥�2.5 or 2 on the
Richter scale鈥攁nd a 1-kiloton nuclear blast is roughly equivalent to a
magnitude 4 earthquake. We鈥檝e got a good capability now.鈥� The CTBT would have
provided for an improved network of seismic sensors to plug holes in existing
coverage. 鈥淭he idea is not to give a potential tester any wiggle room,鈥� says
Park.
It is possible that by hollowing out a large cavity, a state trying to evade
the treaty might be able to set off a small nuclear blast鈥攍ess than one
kiloton鈥攚ithout being detected. But anyone testing a hydrogen bomb or a
boosted weapon would need a yield much greater than that to collect the required
data. 鈥淲e thought you鈥檇 be able to detect tests down to about 1 kiloton,鈥� says
Von Hippel. 鈥淏elow that, there isn鈥檛 much interesting you can do.鈥�
So if the stockpile is safe and geophysicists can detect significant tests,
why was the CTBT kicked out by the Senate? Most believe the explanation is
largely political, not scientific. The President is a Democrat and the Senate
majority is Republican. 鈥淗alf of the Republicans, really, are very sceptical of
arms control,鈥� says Von Hippel. 鈥淎ll of them hate Clinton.鈥� US commentators note
that, during the debate on CTBT ratification, Jesse Helms, the far-right
chairman of the Senate鈥檚 Foreign Relations Committee, thought it relevant to
include references to the Monica Lewinsky affair.
But what effect will the death of the CTBT have on international security?
According to Towle: 鈥淭he Senate vote certainly makes it easier for the Indians
to resume testing if they want. But whether it would tip the balance with a
state that is considering the nuclear arena, such as Iran, is less likely.鈥�
The coup last month in Pakistan鈥擨ndia鈥檚 bitter regional enemy and
itself an emerging nuclear power鈥攈as fuelled concern over the CTBT鈥檚
demise. The new regime in Islamabad, already under international pressure for
introducing martial rule, is unlikely to start rattling nuclear sabres鈥攁t
the moment.
Others are more philosophical. L. K. Sharma, London correspondent
of The Times of India and an authority on Indian defence and foreign
policy, says: 鈥淒eveloping nations do not need encouragement by the US to develop
nuclear weapons. If they have the means and desire they鈥檒l do it anyway.鈥� But
according to Maleeha Lodhi, Pakistan鈥檚 ambassador to the US from 1994 to 1997:
鈥淚t鈥檚 conceivable that before the year was out India and Pakistan would have
been signed up.鈥�
India has declared a moratorium on nuclear tests. But some Western observers
believe that India cannot credibly deliver even small nuclear weapons at the
moment. And Pakistan is behind India. It鈥檚 distinctly possible that both states
(with India taking the lead) may seek to refine their weapons. If Lodhi鈥檚 hunch
is right, the Senate鈥檚 action represents a lost opportunity.
But looking beyond domestic politics and the paranoia over warhead
reliability, some observers detect more calculated thinking on the floor of the
US Senate. There are commercial interests in weapons investment. And John
Simpson, director of the Mountbatten Centre for International Studies in
Southampton, notes that the ascendant 鈥渦nilateralist movement鈥� in US politics is
talking up the issue of missile defence systems again. The Anti-Ballistic
Missile Treaty looks vulnerable. He suspects some right-wingers are looking
forward ten years to a time when the US may be in the position to test new
devices powered by nuclear explosion.
Indeed, senator John Warner, who chairs the Armed Services Committee, says:
鈥淢any of the nuclear systems that we developed to deter the Soviet Union are
simply not suited to the subtle, and perhaps more difficult, task of deterring
rogue states from nuclear, chemical or biological weapons . . . Such weapons do
not exist today in the US arsenal.鈥�
Helms鈥檚 success in having the Arms Control and Disarmament Agency
(effectively a watchdog to stop the Pentagon jeopardising international arms
control agreements) abolished last year fuels such speculation.
If we鈥檙e about to witness a new push on the part of the world鈥檚 only
superpower to subvert science for dubious political ends, it won鈥檛 be the first
time. In the meantime, according to observers like William Walker of St Andrew鈥檚
University: 鈥淚t looks like arms control is falling apart.鈥�
