Nuclear Issues

All the world's nuclear-armed states (except for North Korea) have begun modernizing and upgrading their arsenals, leading many observers to predict that the world is entering a new nuclear arms race. While that outcome is not yet inevitable, it is likely, and if it happens, the new nuclear arms race will be different and more dangerous than the one we remember. More nuclear-armed countries in total, and three competing great powers rather than two, will make the competition more complex. Meanwhile, new non-nuclear weapon technologies — such as ballistic missile defense, anti-satellite weapons, and precision-strike missile technology — will make nuclear deterrence relationships that were once somewhat stable less so.

The risks of nuclear escalation are greater than ever given the possibility of misinterpreted cyber espionage and military strikes against early warning systems. 

"Ukraine's denuclearization had been a controversial issue even as it was negotiated, leaving bitter traces in the country's political and public discourse. As a student of political science in Kyiv in the mid-1990s, I remember being outraged by the sense of injustice: how could the states that rely on their own nuclear deterrents demand the nuclear disarmament of others? More so that one of these states, Russia, has never fully come to terms with Ukraine's independence. Since then, I came to research a doctoral dissertation on the denuclearization of post-Soviet successor states and, in the process, learned a great deal about Ukraine's nuclear disarmament that dispelled many of my preconceptions."

This spring, the United States hosted the fourth and final Nuclear Security Summit in Washington, DC. Senior representatives of more than 50 nations convened to mark the end of an unprecedented international initiative over the last six years to strengthen security measures aimed at preventing nuclear terrorism. During that time, many states made significant progress, but more work is needed.

The 2016 nuclear security summit was a pivotal moment for the decades-long effort to secure nuclear material around the globe. More than 50 national leaders gathered in Washington for the last of four biennial meetings that have led to significant progress in strengthening measures to reduce the risk of nuclear theft.

The defining question about global order for this generation is whether China and the United States can escape Thucydides’s Trap. The Greek historian’s metaphor reminds us of the attendant dangers when a rising power rivals a ruling power—as Athens challenged Sparta in ancient Greece, or as Germany did Britain a century ago. Most such contests have ended badly, often for both nations, a team of mine at the Harvard Belfer Center for Science and International Affairs has concluded after analyzing the historical record. In 12 of 16 cases over the past 500 years, the result was war. When the parties avoided war, it required huge, painful adjustments in attitudes and actions on the part not just of the challenger but also the challenged.

In the United States and Europe, many believe that the best way to prevent Russia’s resumption of its historic imperial mission is to assure the independence of Ukraine. They insist that the West must do whatever is required to stop the Kremlin from establishing direct or indirect control over that country. Otherwise, they foresee Russia reassembling the former Soviet empire and threatening all of Europe. Conversely, in Russia, many claim that while Russia is willing to recognize Ukraine’s sovereignty and territorial integrity (with the exception of Crimea), Moscow will demand no less than any other great power would on its border. Security on its western frontier requires a special relationship with Ukraine and a degree of deference expected in major powers’ spheres of influence. More specifically, Russia’s establishment sentiment holds that the country can never be secure if Ukraine joins NATO or becomes a part of a hostile Euro-Atlantic community. From their perspective, this makes Ukraine’s nonadversarial status a nonnegotiable demand for any Russia powerful enough to defend its national-security interests.

When do states acquire nuclear weapons? History shows that only two types of states decide that the bomb is essential to their security: 1) very powerful states; and 2) weak states that lack ironclad security guarantees.