Asia’s Nuclear Future

It may not happen for some time, or at all, but the next nation that joins the nuclear club will be in Asia.

South America and the Caribbean are nuclear-free under the Treaty of Tlatelolco. Likewise, African countries have foresworn nuclear weapons under the Treaty of Pelindaba. The Treaty of Rarotonga covers Australia, New Zealand, and the Pacific islands, and the Antarctic is covered by a treaty too. Europe is united by Russia’s imperial war against Ukraine and sits under the protection of NATO’s nuclear umbrella. 

More broadly, most nations around the world have promised, under the Nuclear Nonproliferation Treaty (NPT), not to develop or acquire nuclear weapons. Most of those outside the NPT are in Asia. Three of the Asian states outside the NPT are already nuclear powers: India and Pakistan, and North Korea, which withdrew from the NPT in 2003.

Several states in Asia have motives to proliferate, inspired by complex regional conflict dynamics and domestic ambitions alike. North Korea tests missiles. China builds up its nuclear arsenal and patrols the South China Sea aggressively. India, Pakistan, and China contest borders. Iran ratchets up its uranium enrichment. The mix of nuclear and non-nuclear nations and the complexity of the conflicts in Asia can make nuclear weapons look attractive. 

On the other hand, Asia has nuclear weapon free zones too. The Treaty of Bangkok covers Southeast Asia, and Central Asia has its own treaty against nuclear weapons.

Nuclear weapons were developed with 1940s computational and engineering capabilities. Any industrial nation is capable of building them, but an industrial-scale operation is necessary. A nuclear weapons program is expensive and requires significant development and redirection of resources. Not only must the weapons themselves be developed, but delivery systems need to be created too.

A state that wants to develop nuclear weapons would have to withdraw from the NPT, a move that would trigger considerable consequences. Alliances with other states would weaken or be broken, with, for example, sanctions or travel bans imposed. Tensions with adversary states would increase. And ultimately, nuclear weapons cannot prevent conventional conflict, as seen in the Sino-Soviet border war of 1969 and the 1999 Kargil War between India and Pakistan.  

The world’s largest nuclear powers – the United States, Russia, and China – have an outsized influence on proliferation potential in Asia. Their activities may lead other nations to consider developing their own nuclear weapons. 

Asia’s Nuclear Powers

In September 2022, Russian President Vladimir Putin accused the West of “nuclear blackmail” –  threatening to use nuclear weapons against Russia – and had a strong retort: “If the territorial integrity of our country is threatened, we will certainly use all the means at our disposal to protect Russia and our people.”

He went on: "This is not a bluff… those who try to blackmail us with nuclear weapons should know that the weathervane can turn and point toward them."

In this and other ways Russia’s invasion of Ukraine has reverberated in many countries, reminding them that the use of military force always remains possible – and the threat of nuclear war real. Most of Russia’s perhaps 2,000 tactical nuclear weapons are deployed in Asia, and Moscow’s relationships with Iran and North Korea are relevant to potential proliferation.

The war in Ukraine provides a baseline of increased alert, on top of other rivalries that may make nuclear weapons more attractive.

At the same time, China is building up its nuclear arsenal and expanding its military activity. It is a protector of North Korea and a friend of Russia. Its alliance with Pakistan and its own border claims put China in conflict with India, too. Countries in Southeast Asia are wary of China. Its ambitions toward Taiwan potentially put it in conflict with the United States. Its militarization of the South China Sea is of concern to all nations that surround or transit it.

China has recently taken some initiatives to develop its soft power, courting Europe and brokering a deal between Iran and Saudi Arabia to resume diplomatic relations. At the same time, however, Micronesia’s president recently reported considerable Chinese bullying.

China is believed to have about 350 nuclear warheads. Two new fields of missile silos have been observed in northwest China, adding as many as 200 missiles to its arsenal. The purpose of these missiles is most likely to counter the United States, whether as a deterrent or as bargaining chips. If China chooses to fill all the silos with nuclear missiles, they have the plutonium for the warheads. China refuses to discuss nuclear arms control. This potentially weakens the umbrella effect of the U.S. nuclear arsenal for allies South Korea and Japan.

In the past, China likely aided Pakistan’s nuclear weapons program and the proliferation network built by A.Q. Khan. China now seems less inclined to aid proliferators, including North Korea. 

In Northeast Asia, North Korea’s ongoing nuclear missile development, supported by China and Russia, meets U.S. allies South Korea and Japan. It’s here that Asia’s nuclear future is most evident, with a new nuclear test anticipated in North Korea and new discussions about pursuing nuclear weapons in Japan and South Korea.

North Korea is developing missiles capable of carrying nuclear warheads as far as the United States. With only six explosive nuclear weapons tests, they seem to have developed a design that can be carried on their missiles, and signs have been detected of possible preparations for a seventh test. Pyongyang is building a nuclear arsenal, and North Korean rhetoric is fiery and aggressive. No talks are in progress, and the goal of denuclearization of the Korean Peninsula seems unlikely.

North Korean rhetoric particularly targets South Korea. South Korea has always been vulnerable to North Korean conventional attacks. In a war, North Korea would also target U.S. bases in South Korea and Japan.

North Korea’s missile testing pace increased markedly in 2022. The tests were mostly operational, to train the military in missile use, with a few for development. Short-range solid fuel missiles and intercontinental range liquid fuel missiles were tested. Several of the missiles flew over Japan at high altitude, causing alerts. 

In March 2023, North Korea tested a ground-based solid fuel rocket during what it claimed to be a simulation of a nuclear attack on South Korea. The North followed that up with an announced test of an “unmanned underwater nuclear attack craft,” which it said was designed to “make a super-scale radioactive tsunami through underwater explosion.”

Activity at their test site suggests that another nuclear explosive test may be in the works. North Korean leader Kim Jong Un has ordered a buildup of tactical nuclear weapons. It is possible that a smaller device is being developed, although the device they claimed to have tested previously will fit on current ICBMs. 

The number of weapons in North Korea’s arsenal is not easily estimated. Uranium mining continues, and the 5 MW reactor in the Yongbyon Nuclear Scientific Research Center, used for plutonium production, continues to operate. Overhead photos show its operation as it discharges cooling water. Operations to produce plutonium and enriched uranium are within buildings and not observable. From these clues, amounts of fissile material can be estimated, but a further uncertainty is how much of it may have been fabricated into weapons. The size of the weapons is a factor in the estimate, and North Korea has stated its intention to build both high-yield and smaller battlefield weapons.

Hans Kristensen and Matt Korda of the Nuclear Notebook Project estimate that North Korea has fissile material for 45 to 55 nuclear weapons but has likely assembled fewer than that – potentially 20 to 30. Other estimates range to over 100 weapons. Whether these are warheads that can be delivered, particularly at intercontinental distances, is unknown.

North Korea declared a no first use policy after its fourth nuclear test in 2016, but in late 2022 tailored that policy slightly to make an exception for attacks on its sovereignty. 

Kim is firmly in place as North Korea’s leader, and his sister Kim Yo Jong has become a spokesperson for the regime. He has allowed the release of photographs of his daughter with him at missile tests. These activities imply Kim’s plans for succession within his family. At the same time, North Korea is once again experiencing food shortages, with indications of worse to come. 

Another area of great concern when it comes to nuclear conflict is where India, Pakistan, and China come together in a disputed border region. All three are nuclear weapons states, but only China is a member of the NPT. China contributed to Pakistan’s development of nuclear weapons and the two often act in concert. Russia sometimes takes India’s side. Conventional military hostilities between China and India, and between Pakistan and India, have occurred during recent years over border disputes. Pakistani terror attacks within India have also been destabilizing. India and Pakistan have had a ceasefire in place since 2021, but it could be broken by a terrorist attack at any moment.

The 2005 U.S. agreement to supply India with civilian nuclear technology was expected to weaken the NPT, but few consequences are evident almost two decades later. India has shown less interest in acquiring U.S. nuclear technology than the Bush administration anticipated when it made the agreement.

Pakistan, through A.Q. Khan, shared its nuclear technology widely, contributing to proliferation risks around the world. The international industrial network he built has been largely dismembered, but pieces of the technology continue to circulate, for example a design of an enriched-uranium implosion weapon found in Libya.

Pakistan’s push for influence in Afghanistan concerns India, but Islamabad also faces a number of internal challenges, including rebuilding from last year’s floods, serious economic weaknesses, and terrorism by the Pakistani Taliban.

We are not far enough into China’s nuclear buildup to know whether it will provoke India to increase its own nuclear arsenal, which would incentivize Pakistan to increase theirs. India is believed to have about 150 nuclear warheads and Pakistan about 160.

Asia’s Possible Proliferators 

Among Asia’s possible proliferators, there has been heightened discussion of nuclear weapons in Japan and South Korea, while Iran has long been suspected of moving toward nuclear weapons. Taiwan and Myanmar are two other possible proliferators in Asia worth discussing in brief.

Taiwan had a nuclear weapons program from the late 1960s until 1988, when it gave up the effort. Since then, Taiwan’s leaders have committed not to developing nuclear weapons. If Taiwan were to change its policy, a lead time of several years is projected for Taiwan to develop a production capacity. Designing a warhead-delivery vehicle combination could take longer. 

Taiwan cannot hope to compete against China’s 350 and more nuclear weapons and at present there’s no serious discussion of even trying. Although U.S. commitment to defend Taiwan is purposefully ambiguous, one cannot discount the unfurling of the U.S. nuclear umbrella over the island.

Myanmar is a member of the NPT and the Southeast Asia Nuclear Weapon-Free Zone. Despite that, in 2010, photographs supplied by a defector were interpreted to suggest that Myanmar could be developing a nuclear weapons program. The equipment depicted in the photographs is standard laboratory equipment that could be used in a variety of ways – including experiments relevant to developing nuclear weapons. Such experiments might represent the beginnings of such a program, but not necessarily. In 2011, rumors of a Myanmar-North Korea nuclear collaboration were found to have no basis. 

It’s unlikely that Myanmar ever had a significant research program on nuclear weapons, but the earlier rumors have unsettled other nations, particularly since the military coup in 2021. Thus, the U.S. government formally expressed concern at a cooperation agreement between Myanmar and Russia, signed in February 2023. The agreement is for “peaceful use of atomic energy,” and a nuclear reactor in Myanmar is planned.

New nuclear proliferation concerns are more serious when it comes to Japan and South Korea.

South Korea has structured its relations with China carefully to avoid conflict. As North Korea builds up its nuclear arsenal, it indulges in highly inflammatory rhetoric against South Korea, especially around joint South Korea-U.S. military exercises. Much of South Korea is within artillery bombardment distance.

Japan’s concerns are similar to South Korea’s. It hosts U.S. naval and air force bases that are the subject of North Korea’s rhetoric and targeting. It is vulnerable to China’s actions in the East China Sea, where Beijing and Tokyo have a territorial dispute. 

Both Japan and South Korea have nuclear industries that could be reoriented to the manufacture of nuclear weapons.

South Korea has a civilian nuclear industry with 25 operating reactors and three more under construction. It exports nuclear reactors and is building a nuclear power plant in the United Arab Emirates. Its current policy is for nuclear power to provide 30 percent of its energy by 2030. South Korea has no uranium mines or enrichment or reprocessing capability. Seoul had a nuclear weapons program in the 1970s and performed questionable experiments after joining the NPT in 1975, but there is no evidence of more recent activity toward nuclear weapons development.

Japan has a full nuclear fuel cycle, with both enrichment and reprocessing, but it must import uranium. After the Fukushima nuclear disaster, Japan restructured its regulation of the civilian nuclear industry and shut many of its reactors down. Reactors are coming back onstream under the new regulations, and Japan plans for nuclear power to supply 20 percent of its electricity by 2030. 

Japan also maintains a stockpile of separated reactor plutonium. At the end of 2020, the total amount of plutonium was approximately 46.1 tons, 8.9 tons of which was held domestically and 37.2 tons in Britain and France. This reactor plutonium is said to be for mixed-oxide reactor fuel. Japan has a program of fast-neutron reactors that might use it, but the separated plutonium could also be used in nuclear weapons. This possibility is of concern to China, North Korea, and South Korea. 

In January, South Korean President Yoon Suk-yeol suggested that South Korea might explore the possibility of obtaining its own nuclear weapons. North Korea’s buildup, former U.S. President Donald Trump’s threats to remove the U.S. nuclear umbrella, and concerns that Russia’s rhetorical use of its nuclear arsenal may embolden North Korea inform Yoon’s concerns, along with a general feeling that South Korea should be more independent of the United States. Polling from 2022 showed 71 percent of South Koreans as favorably inclined toward developing nuclear weapons. More recently, the mayor of Seoul called for South Korean nuclear weapons.

In December, Japan issued three strategic documents: the National Security Strategy, the National Defense Strategy, and the Defense Buildup Program. These documents describe a more assertive defense posture but stop far short of a nuclear weapons program. Any move toward such a program would have to overcome not just the international consequences, but the steep barrier of Japanese public opinion. Japan has a strong aversion to nuclear weapons after having suffered from the only wartime use of nuclear bombs in 1945.

If the agreement holds between Japan and South Korea on compensation to World War II forced laborers, a big obstacle to their bilateral cooperation, including on North Korea, will be removed. The two states are making progress to work together in other ways as well. 

Meanwhile, the United States and United Kingdom have agreed to provide nuclear-propelled, but not nuclear weapons equipped, submarines to Australia under the AUKUS partnership. These arrangements should increase South Korea’s and Japan’s security and lessen the domestic desire in each for nuclear weapons.

And then there’s Iran, a long-time concern for nuclear proliferation. Iran is surrounded by nuclear powers: It shares borders with Pakistan and NATO member Turkey, where U.S. nuclear weapons are stationed. Russia is on the other side of the Caucasus. Israel, possessor of perhaps 75 nuclear weapons and outside the NPT, is Iran’s prime enemy, publicly threatening to attack militarily and mounting occasional attacks against individuals. 

China buys oil from Iran despite U.S. sanctions, and the United States has long urged China to cease such relations. China recently negotiated an agreement between Iran and Saudi Arabia to reestablish diplomatic relations, underscoring Beijing’s growing clout in the Middle East. 

Negotiations among Iran, China, Russia, the United States, the United Kingdom, Germany, France, and the EU resulted in the 2015 Joint Comprehensive Plan of Action (JCPOA), in which Iran limited its nuclear program in return for sanctions relief. In 2018, however, Trump withdrew the United States from the agreement. In response, Iran ratcheted up its uranium enrichment in increments to press the United States to return to the agreement. Although the Biden administration reopened negotiations with Iran in 2021, the United States has not returned to the agreement, and further progress seems unlikely.

Iran had been in compliance with the JCPOA until the United States withdrew from the agreement. Iran’s interest in a nuclear weapons program has been far from a straight-line dash for a weapon, although news reporting often makes it sound as if it is. Iran received a research nuclear reactor from the United States in 1967, and nuclear research continued after the 1979 revolution. In 2007, the United States released a National Intelligence Estimate (NIE) that Iranian work on nuclear weapons had ceased in 2003 and had not been taken up again at the time of the estimate.

In response to the 2015 U.S. withdrawal from the JCPOA, Iran has incrementally increased its level of enriching uranium and has balked at some International Atomic Energy Agency (IAEA) inspections. Despite this, both CIA Director William Burns and Director of National Intelligence Avril Haines have said that they have no evidence that Iran is actually building a bomb. 

For Iran, nuclear weapons would primarily serve to counter nuclear-armed Israel. They would also have the value of proving the country to be among the elite few capable of building such weapons and would show superiority to Saudi Arabia, with whom the Iranians are fighting in Yemen. 

However, a nuclear arsenal is not within rapid reach for Iran. Without a plutonium-producing reactor, Iran cannot build nuclear weapons small enough to mount on a missile. A plutonium reactor under construction was disabled as a part of the JCPOA in 2016. Full nuclear weapons production capability is probably at least two years away.

Moves toward activating full production capability would likely draw an attack from Israel. Such an attack could not destroy all of Iran’s nuclear weapons capability but would harden Iran’s resolve to build nuclear weapons. 

Because Iran is a party to the NPT, its nuclear facilities are subject to inspection by the IAEA. The JCPOA imposed additional inspection requirements. Recently, the inspectors found a particle of 84 percent enriched uranium. Iran claims that enrichment beyond 60 percent resulted from a mistake, but it is hard to see how that happened. In any case, 60 percent is close enough to produce 90 percent bomb-grade enriched uranium within weeks. Iran recently agreed to allow increased inspections, but the details of those inspections have not been worked out just yet.

Iran’s internal and external relations are in transition, with no clear endpoint. For almost a year, Iran has been racked by protests against its government. Iran supplies arms to Russia for its war against Ukraine, and it supplies oil to China. At the same time, Tehran backs Azerbaijan against Russia-backed Armenia in a small war on its border,and China recently brokered an agreement between Iran and Saudi Arabia to resume diplomatic relations, quite a breakthrough.

Hardline factions that might want to produce a nuclear weapon are far from fully in control in Iran. History suggests that the country uses its potential nuclear weapons program as a threat; paradoxically, a full-fledged production program would not produce leverage in the same way. Closer relations with Russia and China, along with calming down competition with Saudi Arabia, may lessen Iran’s perceived need to acquire nuclear weapons.

Agreements Against Nuclear Weapons. 

More than a score of nations in Asia have signed agreements not to develop or host nuclear weapons or otherwise declared themselves as nuclear weapons free. 

In 2006, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan signed the Treaty on a Nuclear-Weapon-Free Zone in Central Asia, it went into effect in 2009. Mongolia in 1992 declared itself nuclear weapons free, as did New Zealand in 1987. The Treaty on the Southeast Asia Nuclear Weapon-Free Zone – including Brunei Darussalam, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam – came into effect in 1997.

Asian signatories to the Treaty on the Prohibition of Nuclear Weapons (TPNW) include Bangladesh, Cambodia, Indonesia, Kazakhstan, Laos, Malaysia, Mongolia, Nepal, Philippines, Seychelles, Thailand, Vietnam, and some of the Pacific island states such as Fiji and Vanuatu.

The NPT is the basic treaty in which states agree not to build nuclear weapons. Nuclear weapon free zones, such as those mentioned above, are formed under it. The TPNW, meanwhile, declares building or holding nuclear weapons to be against international law and is another layer of protection against proliferation. 

No current nuclear weapon state, nor the states that depend on their nuclear umbrellas, however, is likely to join the TPNW. States can withdraw from treaties, of course, but North Korea is the only state that has withdrawn from the NPT so far. 

Where Is the Next Nuclear Power?

Even in today’s unsettled environment, the prospects for additional states to develop nuclear weapons are low. But if there is a next nuclear power, it’s to be found in Asia. Iran is the most likely, but its history suggests that it values the threat of developing a nuclear weapon as leverage more highly than actually producing the weapons themselves. South Korea and Japan are concerned about North Korea and China, but their relatively short latency periods to nuclear weapons allow them to test the waters with rhetoric first. Taiwan and Myanmar are not proliferation threats at this time.

The situations for these potential proliferators are changing rapidly. A breakthrough in negotiations could greatly limit Iran’s potential, but that is highly unlikely. China has recently shown willingness to aid stability in the area by brokering the resumption of diplomatic relations between Iran and Saudi Arabia. Iran is jousting for influence in Afghanistan with Pakistan, which could make proliferation more likely, but again, China may act as a stabilizer.

A continuation of China’s aggressive maritime operations, however, could add to Japan’s and South Korea’s motivations toward proliferation. More negotiations with North Korea are needed to freeze its arsenal and slow down its bellicosity, but there is no prospect for such talks in the immediate future.