Nuclear Issues

Joseph Nye considers lessons from his own work on preventing the spread of nuclear technology in the 1970s.

This year's G7 summit in Hiroshima sees nuclear disarmament and non-proliferation sitting high on the agenda, amid rising tensions between the nuclear states and an increasingly divided international order.  Six contributors offer their analyses, including the Belfer Center's Mayumi Fukushima.

Chinese strategists increasingly believe that U.S. nonnuclear strategic capabilities threaten China’s nuclear forces. Although there is limited evidence of a shift in its nuclear strategy, China is changing its strategic posture to ensure its second-strike capability, including by relying on advanced conventional weapons (e.g., counterspace capabilities, cyber weapons, and electronic warfare) that can target U.S. missile defense. The dynamics of a nuclear-conventional entangled security dilemma may weaken arms race stability.

Earlier this month, South Korean President Yoon Suk-yeol set off alarms. In an off-the-cuff remark, he warned that Seoul might need to develop nuclear weapons—or demand redeployment of U.S. nuclear arms to the Korean Peninsula—to counter North Korean nuclear threats. In doing so, Yoon spotlighted a popular view once reserved for hawkish commentators, defense intellectuals, and former military officials. Keeping nuclear weapons out of South Korea will ultimately be a U.S. responsibility that requires addressing both the deteriorating security environment and the domestic drivers underlying Yoon’s statement.

For months, evidence has accumulated that North Korea may be preparing its seventh nuclear explosive test. Continuous warnings by analysts and the media about this possibility are a sobering reminder that Pyongyang's continued pursuit of a larger nuclear arsenal remains a challenge for the Non-Proliferation Treaty and the nonproliferation regime. This continues to be the case even as the public and leaders around the world have largely shifted their attention to the nuclear dimensions of the war in Ukraine.

An analysis of Taiwan’s military value concludes that its reunification with China would improve Chinese submarine warfare and ocean surveillance capabilities, tipping the military balance in China’s favor. These findings have important implications for U.S. operational planning, policy, and grand strategy.

Recent quantitative scholarship uses warhead counts to examine whether nuclear superiority offers political or military benefits beyond having a secure second-strike capability. These analyses overlook other elements of a state’s nuclear capability such as state perceptions and beliefs.

The costly Ground-based Midcourse Defense system remains unproven and unreliable in deterring North Korea’s threat to use intercontinental ballistic missiles. An airborne boost-phase intercept system may offer an alternative defense against North Korea without threatening Russian or Chinese deterrents.

Under the guidance of its self-defence nuclear strategy, China will continue to modernise its nuclear force in order to maintain a reliable second-strike retaliatory capability. China’s nuclear weapon modernisation has been responsive to the advances of military capabilities of other countries, particularly the US. As Hu Side emphasised, “The sole purpose for China to maintain a limited nuclear counterattack force is to deter a potential nuclear strike. However, the development of US missile defense and the long-rang strike capability with high accuracy to target mobile missiles is in practice to decrease the effectiveness of Chinese nuclear deterrence. Thus, it surely leads to Chinese attention."

Recently published documents, news reports, and other sources of open source information indicate that China is accelerating its current nuclear force modernization programme. It is clear that it is driven largely in response to the growing United States (U.S.) missile defense program, which China perceives as a threat to its minimum credible deterrence. While China is not altering its nuclear doctrine, it believes that it needs to enhance the reliability, survivability, and effectiveness of its retaliatory capability in response to a first-strike. In addition to expanding the size of its nuclear arsenal, it is enhancing its delivery capabilities, for example, by increasing the number of ICBMs and making them more sophisticated. It is building more Multiple Independently Targetable Reentry Vehicle (MIRV) warheads as well as a new class of ballistic missile submarines. China’s ongoing nuclear modernization aims to increase the survivability, reliability, safety, and penetration capability of its small nuclear arsenal and thereby assures a limited, reliable, and effective counterattack capability that will deter a nuclear first-strike. China’s nuclear modernization program will likely continue to be guided by its nuclear policy, which is characterized by a no-first-use pledge and a commitment to “minimum nuclear deterrence.” Finally, while China supports the total elimination of nuclear weapons, it does not believe it is in China’s interest to participate in discussions about nuclear disarmament until the U.S. and Russia reduce their arsenals to one thousand each, or lower.