Nuclear Issues

In this Q&A, Joseph S. Nye talks about his advice for the interim and future president of Harvard in the wake of Claudine Gay's resignation, which countries should be highest on our radar to prevent the threat of nuclear war, what role the U.S. should play in the Russia-Ukraine war, the significance of U.S. alliances in the Middle East, and more.

At a moment when arms control is deeply troubled and may be dying, two eminent scholars, Marc Trachtenberg and the late Robert Jervis, have taken a fresh look at the beginnings of strategic arms control fifty years after the signing in Moscow of the SALT I agreements in May of 1972. They do so from different vantage points, writes Steven E. Miller.

Calder Walton says both seek to topple the United States from atop world stage, with China's blend of money, influence, all-hands-on-deck approach posing the greater threat.

According to the "Madman Theory" outlined by Daniel Ellsberg and Thomas C. Schelling, and embraced by Presidents Richard Nixon and Donald Trump, being perceived as mad can help make seemingly incredible threats—such as starting a nuclear war—more credible. However, recent research has largely concluded that the Madman Theory does not work. 

Scott Sagan asked Joseph S. Nye to revisit Nuclear Ethics, a book he published in 1986, in light of current developments in world affairs. In doing so, he found that much had changed but the basic usability paradox of nuclear deterrence remains the same. 

In a conversation with the Harvard Gazette's Alvin Powell, Allison discussed lessons of the John F. Kennedy-Nikita Khrushchev standoff, hard decisions facing President Biden, and the prospect of a cornered Putin. The interview has been edited for clarity and length.

How robust is public support for extended nuclear deterrence in patron and client states? Recent studies have improved scholarly understanding of US public opinion about nuclear weapon use against non-nuclear adversaries. Yet, there is limited knowledge of public attitudes regarding retaliation for nuclear strikes against US allies. We develop a theoretical typology of nuclear crises and investigate this phenomenon with a novel survey experiment (n = 6,623). Americans, Japanese, and South Koreans viewed realistic emergency alert messages about a most-likely case for nuclear retaliation: a North Korean missile attack on a US ally protected by the nuclear umbrella. Support for nuclear retaliation is low in all three countries, with important cross-national differences. Favorability increases with North Korean nuclear first-use, but it remains limited nonetheless. Surprisingly, US “tripwire” troop casualties do not increase Americans’ demands for nuclear retaliation. These findings have important implications for the study of nuclear crises and practice of extended deterrence.

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.

Could a conventional war between China and the United States escalate to the nuclear level? An assessment of three mechanisms of China-U.S. inadvertent escalation—use-it-or-lose-it, unauthorized/accidental, and damage limitation—concludes that the risk of China-U.S. inadvertent nuclear escalation is extremely low.