The Law of Small Numbers

• DOI: 10.1177/0022002702046004001
• Date: 01 August 2002
• Published date: 01 August 2002
• Author: JAMES H. LEBOVIC
• Subject Matter: Articles

JOURNALOFCONFLICTRESOLUTIONLebovic/THELAWOF SMALL NUMBERS

The Law of Small Numbers

DETERRENCE AND NATIONAL MISSILE DEFENSE

JAMES H. LEBOVIC

Department of Political Science

George WashingtonUniversity

Armed with a new threat and promising technology,advocates of national missile defense (NMD) have

framedthe debate by presenting NMD as a break from traditional deterrence principles. The assumption that

the United States facesnew adversaries that cannot be deterred by U.S. offensive options and whether adver-

saries can and will use nuclear weapons to coerce the United States, givenits inclination and ability to retali-

ate,are assessed. The effectiveness of NMD against various offensivethreats is simulated. Conclusions indi-

cate that NMD advocates have not made their case that cold war–era deterrence principles are ill suited to

U.S. relations with fledgling nuclear states and that the expected value of a missile defense of any type and

scaleis low because it is unlikely to enhance global security above levels offered by retaliatory deterrence.

The issue of missile defense is back on the U.S. policy agenda. Policy makers in the

George W.Bush administration are pushing to build a national missile defense (NMD)

system to defend the United States in the near future against a small-scale missile

attack. They insist that defensive technology is too promising and its purposes are too

important to be diluted in debate. They claim that opponents unfairly discount the

blessings that technology can deliver and denythe obvious: the world’s most irrespon-

sible and ruthless leaders will soon possess the most destructive weapons that the

world has known. For these and other proponents, then, defense is a rational (if not

moral) response to fledgling nuclear adversaries—so-called “rogue states” (especially

Iran, Iraq, and North Korea)1—that eschew traditional rules of restraint and possess

small arsenals against which the United States could credibly defend. The case for

missile defense is only strengthened, proponents argue, by the horrific terrorist attack

on the WorldTrade Center in New York, which provesonce and for all that the United

States faces a new nemesis, one that will go anywhere and do anything to accomplish

its goals.

455

AUTHOR’SNOTE: I wish to thank my colleagues, Debbie Avant,Jim Goldgeier, Eric Lawrence, Henry

Nau, Marc Raskin, David Shambaugh, Lee Sigelman, and Langche Zeng for their thoughtful remarks on

earlier versions of this article.

JOURNAL OF CONFLICT RESOLUTION, Vol.46 No. 4, August 2002 455-483

© 2002 Sage Publications

1. For convenience, I refer to rogue states throughout this study. As should be apparent, I do not

accept many of the assumptions that typically accompany this pejorative label.

In making their case, however,proponents have muddied the relationship between

long-standing U.S. deterrence policies and missile defense. Some proponents insist

that defense and retaliatory deterrence are complementary responses to the new threat

but that defenses can “negate the potential of regional adversaries” and render an

attack “not only fatal, but futile” (Slocombe 2000, 80).2Defense enthusiasts (includ-

ing the president and congressional Republicans) make an even stronger argument.

They maintain that defenses will eradicate the nuclear threat from leaders who cannot

be deterred by the threat of punishment (retaliatory deterrence). Indeed, one commen-

tator criticized opponents of missile defense for “sporting Cold War arguments so

comically anachronistic you have to wonder whether they’llever offer a serious argu-

ment on nuclear weapons” (Krauthammer 2001, A45). In contrast, for cautious sup-

porters of a limited NMD system, defenses must be balanced against deterrence:

defenses offer some insurance should deterrence fail, but defenses can undercut deter-

rence if they overreach their potential or aggravatethe global nuclear threat (Daalder,

Goldgeier, and Lindsay 2000; Lindsay and O’Hanlon 2001).3It is useful, then, to

rediscover“lost” cold war deterrence arguments, juxtapose them with current thinking

about missile defense, and explore the implications of these assertions giventhe likely

performance and vulnerabilities of an NMD system. Through this analysis, the dilem-

mas and risks of NMD become apparent: to an extent unappreciated even by cautious

supporters of a limited NMD system, defenses do not replace retaliatory deterrence

and can undermine it.

That policy makers and analysts have neglected the old nuclear debate is under-

standable, for much of its reasoning was hypothetical, arcane, and counterintuitive. It

is less understandable in light of the conviction with which nuclear strategists held to

their positions. At the center of the debate were those who maintained that the United

States and Soviet Union would not attack each other because retaliation would be

quick, certain, and devastating. Their conception of deterrence was embodied in the

1960s in U.S. assured destruction (AD) doctrine, which had the United States prepar-

ing to withstand a worst-case Soviet first strike and then render damage in return (a

second strike) that met established AD criteria (that between one-quarter and one-third

456 JOURNAL OF CONFLICT RESOLUTION

2. National missile defense advocates do sometimes clarify the relationship between retaliatory

deterrence and defense. On the “twosides of deterrence,” see, for example, W.B. Slocombe, Undersecretary

of Defense for Policy in the Clinton administration, Remarks to the Center for Strategic and International

Studies Statesmen’s Forum(Washington, DC: Center for Strategic and International Studies, November 5,

1999,retrieved from http://www.csis.org/html/sf991105Slocombe.html). Their specific argumentssuggest,

nonetheless, that traditional deterrence thinking is inapplicable.

3. Whether a system is “limited” in architecture is in the eye of the beholder.Consequently, I use the

term cautious supporters to distinguish those who propose that the United States acquire the capability to

defend itself from a handful of rogue state missiles and strongly appreciate the physical limits of defensive

technology and its confounding political and strategic effects. Although much of the current controversy

centers on Bush administration efforts to construct a defense with the capability to attack warheads in their

midcourse phase as part of a layered defense that might also attack long-range missiles in their boost phase

or warheads at their terminal (atmospheric reentry) phase, evencautious supporters lend support to a small-

scale, midcourse defense (Daalder, Goldgeier, and Lindsay 2000; Lindsay and O’Hanlon 2001). Unless

stated otherwise, though, my arguments apply to all manner of national missile defense (NMD) systems

intended to defend against long-range missiles. (For an excellent discussion of these systems, see Lindsay

and O’Hanlon 2001.)