All nuclear weapons require plutonium or highly enriched uranium—also known as fissile material—in order to deliver their tremendously destructive effects.
Producing fissile material is not easy, nor is it inexpensive. Enriching uranium to bomb-grade levels requires a sophisticated industrial capability and the continuous operation of thousands of sensitive centrifuge machines. Plutonium is produced is small quantities through the irradiation of fuel rods in nuclear reactors and then must be separated and purified by means of a complex chemical process for use in a nuclear weapon.
Nevertheless, the world is awash in fissile material. As of 2010, the global stockpile of highly enriched uranium was approximately 1,475 metric tons, which is enough for about 60,000 nuclear weapons. About 98% of this material is held by the world’s nine nuclear-armed countries. The global stockpile of separated plutonium is about 485 metric tons, 98% of which is held by the nuclear weapon states, while the remainder is for civil nuclear energy programs of non-nuclear weapon states and under international safeguards.
Halting the further production of fissile material is an essential part of curtailing nuclear arms competition, curbing the spread of nuclear weapons to additional states, and reducing the risk that some nuclear weapons-usable material may be lost, stolen, or sold to terrorists.
Since building up its own stockpile off fissile material during the early decades of the Cold War, the United States has sought to verifiably halt the production of fissile material for weapons purposes. Along with the United States, Russia, the United Kingdom, and France have all publicly declared a halt to fissile material production for weapons. China is believed to have halted production for weapons purposes. Israel retains a fissile production capability outside of safeguards, but is not believed to be producing more material.
North Korea has a small plutonium-production capacity and claims to have a uranium enrichment facility, which it is legally obligated to put under inspection and shut down. Iran is expanding its uranium enrichment facility at Natanz, but it under international inspection and Iran has not yet enriched uranium to weapons grade.
Nuclear-armed neighbors, India and Pakistan, however, remain in a fissile production “race.” India produces plutonium for weapons at two military production reactors and is estimated to have about 700 kilograms of separated plutonium, which is enough for about 140 bombs. It produces new plutonium at a rate of about 30 kilograms per year.
Pakistan has about 2 metric tons of HEU for its nuclear weapons and about 100 kilograms of weapons plutonium, which is enough for about 100 bombs. Pakistan has one plutonium-production reactor, is building three additional military production reactors, and is increasing its reliance on plutonium weapons. Each reactor can produce about 10 kilograms of plutonium per year.
But since the late 1990s, the concept has been relegated to the diplomatic shadows as talks on a global verifiable fissile material cutoff treaty (FMCT) have sputtered due to differences over negotiating priorities at the 65-nation Conference on Disarmament in Geneva.
In 2009, President Barack Obama pledged to “lead a global effort” to negotiate a verifiable fissile material cutoff treaty but Pakistan has used the consensus decision-making rule in order to prevent negotiations from starting.
Although Pakistan and its nuclear-armed rival India each have more than enough nuclear firepower to deter a nuclear attack by the other, Pakistani leaders consider the proposed FMCT a “clear and present” danger because it would prevent Pakistan from matching India’s fissile stockpile and production potential. Pakistan insists that other nations agree to discuss limits on existing fissile material stocks before talks can begin.
Many states, including the United States, are frustrated with the lack of progress and have said they will pursue other options if Pakistan leaders refuse to allow the Conference on Disarmament to begin negotiations fissile material production cutoff treaty.
One option would be to begin open-ended talks involving states with facilities capable of producing fissile material for weapons, as well as representatives from other key states. The initial focus could be to increase transparency and confidence regarding fissile production and fissile stocks and begin technical work on a targeted system for verifying a production halt.
Even if talks on a verifiable, global FMCT begin, they may last many years. To hasten progress, the five original nuclear-weapon states—the United States, Russia, United Kingdom, France, and China—could negotiate a treaty to halt fissile production and invite other states to join. A similar proposal was advanced by the George W. Bush administration.
Such steps could advance progress while maintaining pressure on Pakistan and India to exercise greater restraint. For Israel, which does not need more fissile material for its military program and has an aging reactor at Dimona, the moratorium would make a virtue out of necessity. The most effective approach vis-à-vis Iran would be to increase the reach of international inspectors to guard against a secret facility that could be used to produce material for weapons and to persuade its leaders to stop expanding its enrichment program, which would cap its fissile production potential.
None of these options is easy or simple, but too much time has already been wasted. States that are truly serious about reducing the nuclear threat now must provide the leadership needed to build a more effective fissile material control system.