Nuclear proliferation

Chapter 21

Nuclear proliferation

By Sheena Chestnut Greitens

Introduction

Nuclear weapons technology and its spread           

Theoretical debates about nuclear proliferation  

Evolution of non-proliferation efforts           

Conclusion          

Reader's Guide

This chapter examines the enduring importance of nuclear proliferation and non-proliferation efforts in world politics since 1945. The chapter begins by explaining some of the technical aspects of nuclear weapons technology, and describes the spread of this technology over time. It then considers major theo­retical debates about nuclear proliferation, including why states want nuclear weapons and what effect they have on patterns of international conflict and cooperation. The chapter next looks at the evolution of various attempts by the international commu­nity to control or limit the spread of nuclear weap­ons. Throughout, it examines how globalization has shaped the global landscape of nuclear proliferation, and how it is likely to shape the issue in the years to come.

Introduction

The spread of nuclear weapons technology continues to be an important issue in a globalized world. The United States’ explosion of the world’s first atomic bomb in a New Mexico desert in 1945 marked the beginning of the ‘Atomic Age’, and nuclear weapons were used for the first and only time against the Japanese populations of Hiroshima and Nagasaki at the end of the Second World War in August 1945. These events demonstrated the extraordinary destructive power of nuclear weap­ons, a fact that has had long-term consequences for international peace and security.

Since then, basic nuclear technology that can be used for either civil or military purposes has diffused widely across the globe. Nuclear weapons themselves have spread

much more gradually, with four additional nuclear pow­ers by 1965, and only nine today. At the same time, the absolute number of nuclear weapons in existence has declined, as the United States and Russia have sought to reduce the number of nuclear weapons in their arsenals.

Globalization and the end of the cold war have introduced new and complex challenges related to nuclear proliferation. These include the growth of nuclear energy, the challenges of loose nuclear weapons and nuclear terrorism, the problmes of nuclear strategy outside the superpower/bipolar context, and continued debate over nuclear weapons programmes in Israel, Iran, and North Korea. As proliferation challenges have evolved, so have international efforts to address them.

Nuclear weapons technology and its spread

Since 1945, civil and military nuclear technology has spread across the globe. Nuclear weapons, however, have been much slower to spread. By 1965, four coun­tries in addition to the United States had tested nuclear weapons: the Soviet Union (Russia), Britain, France, and China. These five were recognized as nuclear weap­ons states under the 1968 Nuclear Non-Proliferation Treaty (NPT), and are also the five permanent mem­bers of the United Nations (UN) Security Council. Only nine countries are thought to possess nuclear weapons today: the five nuclear weapons states, plus India, Pakistan, North Korea, and Israel. Several other states have developed or inherited nuclear weapons arsenals, but have chosen to relinquish them.

Technical basics: what is a nuclear programme?

Nuclear technology is dual-use, meaning that it can be used either to generate energy in a nuclear reactor, or to make a nuclear weapon. A nuclear reactor uses nuclear chain reactions in a sustained, controlled pro­cess to generate power in the form of heat. A nuclear weapon, on the other hand, seeks to create a large explosion using one of two methods: fission or fusion. The earliest nuclear weapons were fission weapons, which split atoms in a chain reaction to release large amounts of energy. By the mid-1950s, however, both the United States and Soviet Union had also developed

thermonuclear weapons, which use a combination of fission and a method called fusion, which compresses and heats hydrogen atoms so that they combine, or fuse, to generate energy.

Developing a nuclear weapon from scratch requires an array of sophisticated technologies arranged in com­plex organizational patterns. This is one reason why the creation of a full nuclear programme is difficult, and has been achieved only by a handful of states willing to devote the attention and resources needed.

One of the most difficult steps in making a nuclear weapon is obtaining weapons-grade fissile material. The two major kinds of fissile material used in the mak­ing of nuclear weapons are plutonium and uranium. Making a nuclear weapon from uranium requires Uranium-235 (U-235), which is a very small fraction of the uranium found in nature (around 0.7 per cent). U-235 must therefore be separated from the non-fissile isotope U-238 through a process called enrichment. Once the uranium has been enriched to 20 per cent or more of U-235, it is called highly enriched uranium (HEU), and above 90 per cent is considered weapons- grade uranium. Plutonium, on the other hand, is cre­ated by humans as a by-product of reactor processes, and must then be reprocessed, or chemically separated from the non-fissile material in spent fuel, in order to be used in a nuclear warhead.

Once this weapons-grade fissile material has been obtained, it must still be weaponized, or made

into a warhead that can be delivered to its intended target. Uranium and plutonium can both be used to make implosion-type bombs, in which explo­sives around a mass of fissile material implode the fissile material to reach critical mass and start the nuclear reaction. Uranium, however, can also be used to make a gun-type bomb, in which one piece of uranium is fired into another to achieve critical mass.

Because of their explosive capacity, nuclear weapons are considered weapons of mass destruction (WMD), along with chemical, biological, and radiological weap­ons, sometimes abbreviated together as CBRN. The explosive yield of nuclear weapons is measured in kilo- tons (thousands of tons) of TNT equivalent, or in mega­tons (millions of tons). Fission nuclear weapons, the kind of weapon dropped on Hiroshima and Nagasaki, can release energy equivalent to tens of thousands of tons of TNT; the destructive capacity of the fusion or ther­monuclear weapons developed later reached as much as several megatons. Nuclear weapons release their energy, and can therefore cause damage, in three different ways: a blast; thermal radiation (heat); and nuclear radiation. Nuclear weapons also cause an electromagnetic pulse that can disrupt the operation of electronic equipment, as well as fires that create further damage (Eden 2006).

Globalization has heightened concern that a non­state actor such as a terrorist organization or criminal group might try to acquire a nuclear weapon or radiolog­ical material—the kind that could be used in a so-called ‘dirty bomb’ (Allison 2005). Because of the complexity of establishing a full nuclear programme, these actors are generally expected to acquire a nuclear weapon by stealing one or purchasing it on the black market, rather than developing it themselves. Concern about nuclear theft has been particularly acute since the dissolution of the Soviet Union—the only time that a state with a nuclear arsenal experienced political disintegration. Command and control arrangements over those weap­ons became questionable. In response, the United States and the international community launched a series of efforts to secure nuclear materials in the countries of the former Soviet Union. More recently, the discovery of the global proliferation network run by Pakistani scientist A.Q. Khan raises concerns that in a globalized world states will not be able to control the diffusion of nuclear materials, technology, and knowledge.

Nuclear proliferation since 1945

During the cold war, the superpowers built large arsenals of nuclear weapons, with widely ranging yields and a

number of different delivery vehicles. Some of the weap­ons were smaller, tactical nuclear weapons, which are generally intended for use against targets on the battle­field and so are delivered by methods like aircraft, artil­lery, or short-range ballistic or cruise missiles. Others were strategic nuclear weapons, typically with larger yields, delivered by means such as long-range bombers, land-based intercontinental ballistic missiles (ICBMs), or submarine-launched ballistic missiles (SLBMs). Starting in the 1970s, some of these missiles carried mul­tiple independently targetable re-entry vehicles (MIRVs), which meant that a single missile could carry multiple warheads that could strike different targets.

Thinking about nuclear weapons during the cold war focused primarily on the bipolar competition between the United States and the Soviet Union. The main question was how to prevent conventional or nuclear war between the superpowers. A huge body of literature examined nuclear deterrence—the question of ‘how nuclear weap­ons could be used to prevent an opponent from taking an undesirable action’ (Walton 2013:198). Thomas Schelling (1980) famously discussed deterrence as ‘the threat that leaves something to chance’—the idea that if there was even a small risk that conventional attack would cause an opponent to escalate to nuclear conflict in response, that risk would deter the conventional attack.

More concretely, the United States and its North Atlantic Treaty Organization (NATO), allies feared that the Soviet Union would take advantage of its conven­tional military superiority to invade Western Europe; they relied on the threat of nuclear retaliation to prevent it from doing so. To deter the Soviet Union, the United States and its allies used two different nuclear targeting strategies. In a counterforce strategy, American nuclear weapons targeted the Soviet Union’s nuclear and con­ventional military assets. In a countervalue strategy, the assets threatened with nuclear retaliation were targets of industrial or social value, typically cities with large populations. The USSR’s nuclear strategy during the cold war evolved as well, as the Soviet arsenal grew in size and the country’s leaders considered the utility of nuclear weapons for deterrence and war-fighting purposes.

The United States also developed what was known as extended deterrence—the threat of nuclear response in order to deter an attack on one of its allies. This, how­ever, created a dilemma: if an attack on an American ally led the US to retaliate with nuclear weapons against the opponent’s home territory, that opponent might itself retaliate by using nuclear weapons against American soil. Was the US really willing to trade New York for Paris, or Los Angeles for Berlin?