The importance of nuclear testing

By James H. McNally
Washington Times, 13 October 1997

President Clinton’s claim that the
Comprehensive Test Ban is the
“longest-sought hardest-fought prize
in the history of arms control”
certainly is an attention getter. I
wonder if those who sought to control gun
powder centuries ago would agree.
However, in today’s context, perhaps the
exaggeration can be excused. The
“hardest-fought” comment may
refer at least in part to the
difficulties political authorities have
had overcoming justified technical
concerns regarding nuclear-weapon
maintenance. For decades, technicians
responsible for nuclear weapons, not only
in the United States, have expressed
their concerns over prohibitions on
testing, an important part of the
technical process of weapon assessment.

Only actual testing can prove with
certainty that judgment in modeling and
extrapolating from laboratory experience
works. The presence or absence of a Cold
War, for instance, is irrelevant. In the
past, testing has also had the important
human consequence of providing a direct
reminder for the technicians of the power
of these explosions and the dimension of
possible mistakes in judgment. Technical
conservatism, not to be confused with
political conservatism. Certainly
mistakes in judgment are more likely with
passing time as the realities of test
experience become more remote. Lacking
realistic testing, will the next
laboratory-bound generation charged with
the care and feeding of aging weapons
become more prone to overconfidence,
resulting in Chernobyl-like mistakes?

Some may claim the so-called escape
clause in the treaty provides protection
from declining technical confidence.
Beyond the fact that this declining
confidence may not be recognized without
testing, U.S. disavowal of a ratified
treaty has no precedent in recent times.
The technicians are presented with
another major problem. If a stockpile
problem is suspected, how do they make
the case that testing must be resumed at
once – as opposed to resumption a year or
two later, say? Political authorities
work within short time horizons;
postponement for a year at a time for a
few years means the decision will likely
be someone else’s problem.

The British faced this problem during
the 1960s and early ’70s with a nine-year
testing hiatus. Confidence within the UK
weapons program concerning UK warhead
technology and deterrence declined with
passing time. But the case for prompt
testing resumption could not be made
since an unambiguous, politically
credible argument could not be
constructed. The problem was resolved and
testing resumed only after the
Soviet-U.S. ABM Treaty made it clear
politically that UK deterrence might be
jeopardized by anti-ballistic missiles
protecting national capitals. Note well
that this had only been a unilateral
suspension of testing on the British
part; international pressures against
treaty withdrawal or abrogation were
absent. We cannot anticipate a more
favorable outcome under the U.S. system;
human nature and governmental decision
processes are too similar.

There is additional confusion
regarding nuclear-weapon proliferation
and its relationship to a Comprehensive
Test Ban. The five so-called
nuclear-weapon nations have developed
nuclear weapons that are the product of a
complex blend of technologies. This blend
has resulted in sophisticated weapons
that are not amenable to modeling in all
aspects. A very different situation is
present for non-nuclear (or
“emerging”) nuclear-weapon
nations. These countries may elect a
nuclear-weapon capability that involves
straightforward, less-capable nuclear
weapons that do not rely on testing. Here
the technical issue is centered on
conservative safety and reliability
engineering that may or may not receive
emphasis, depending on the country, its
political goals and its technical
capabilities. It is difficult to imagine
how a Comprehensive Test Ban limits these
emerging nuclear-weapon nations. In fact,
with a Comprehensive Test Ban, the
emerging nuclear-weapon nations may feel
they can more readily catch up to the
nuclear-weapon states.

The practical effect of ratification
is to lock the other established
nuclear-weapon countries into an
irreversible treaty trap. If the ban is
ratified, we will see firsthand in the
coming decades how eroding stockpile
confidence is handled by the five of us
in the nuclear club. Pressures among the
five to conduct at least unverifiable
nuclear-yield tests will increase. All of
this is in a framework of no agreed path
or thinking regarding the future role of
nuclear weapons.

James H. McNally was deputy
assistant director for Verification and
Intelligence of the U.S. Arms Control and
Disarmament Agency from 1986 to 1988. He
worked over two decades in the nuclear
weapon program at Los Alamos National
Laboratory.