Paul Poast is an associate professor in the Department of Political Science at the University of Chicago and a nonresident fellow at the Chicago Council on Global Affairs.<\/p>\n\n\n\n
BLUF<\/strong><\/p>\n\n\n\n Overall, assessing the deterrence credibility of nuclear weapons, or deterrence in general, is extremely difficult. That is because we never observe deterrence. We only ever observe the failure of deterrence<\/strong>.<\/p>\n\n\n\n French President Emmanuel Macron\u2019s recent speech at the Sorbonne on his vision for the European Union, as well as his follow-up interview with The Economist, have attracted a lot of attention\u2014as Macron intended. Never one to mince his words, Macron warned that \u201cEurope can die\u201d and expressed a sense of urgency in defeating Russia in Ukraine, even to the point of refusing to rule out sending French troops there in support of Kyiv.<\/p>\n\n\n\n While these comments made headline-grabbing news, another topic he touched on merits further attention: nuclear weapons.<\/p>\n\n\n\n In his speech at the Sorbonne, Macron stated, \u201cNuclear deterrence is at the heart of France\u2019s defense strategy. It is therefore an essential element in the defense of the European continent.\u201d In the Economist interview, Macron made his point more explicitly, saying that he was prepared to make France\u2019s nuclear weapons available to protect the whole of Europe. Macron even referenced former French President Francois Mitterrand, and rightfully so. Back in the late 1980s, Mitterrand assured his West German counterpart, then-Chancellor Helmut Kohl, that France\u2019s arsenal could be \u201cthe nuclear deterrent of Europe\u201d in a bid to convince him to reject U.S. forward-deployed nuclear weapons on the continent.<\/p>\n\n\n\n If Macron\u2019s comments weren\u2019t enough to raise the nuclear stakes in Europe, Russia announced it will conduct a series of drills to simulate using so-called tactical or battlefield nuclear weapons in Ukraine. The drills were a direct response to Macron\u2019s suggestion of putting French boots on the ground in Kyiv and yet another instance of Russian nuclear saber-rattling in order to dissuade further Western support to Kyiv.<\/p>\n\n\n\n All of this raises a fundamental question, one that goes beyond Macron, France, Russia and European security: Are nuclear weapons actually an effective deterrent? Just a few weeks ago, following a large-scale missile and drone attack by Iran on Israel, disarmament activists highlighted how Iran\u2019s behavior\u2014namely, its willingness to attack a country known to possess nuclear weapons\u2014seemed to belie the idea that the possession of nuclear weapons facilitates deterrence.<\/p>\n\n\n\n Nuclear weapons states may indeed be dissuaded from launching massive nuclear attacks against one another, knowing that doing so would invite an equally massive response. This extreme scenario of \u201cmutually assured destruction\u201d admittedly worried many during the Cold War. But what about a scenario far below this threshold? What if, for example, Putin were to launch a nuclear strike on Ukraine using a single low-yield weapon? Would the United States, which is the primary provider of NATO\u2019s \u201cnuclear umbrella,\u201d be willing to authorize an in-kind retaliatory strike? The doubts such a scenario raise make it seem perfectly reasonable to question the deterrent efficacy of nuclear weapons.<\/p>\n\n\n\n Overall, assessing the deterrence credibility of nuclear weapons, or deterrence in general, is extremely difficult. That is because we never observe deterrence. We only ever observe the failure of deterrence. When Russia attacked Ukraine, both in 2014 when it initially took the Crimean Peninsula and in 2022 when it launched a full-scale invasion of the country, it was clearly not deterred.<\/p>\n\n\n\n nuclear weapons in tipping a balance of power and creating deterrence, it is again difficult to discern the effect of the nuclear weapons from other factors that enhance deterrence. Consider North Korea. It is unclear whether the possession of a nuclear bomb is necessary for North Korea\u2019s security, given that it has a large military amassed on its border with the South and tens of thousands of conventional missiles targeting Seoul, just 30 miles away. The onset of war on the Korean Peninsula would be devastating\u2014and therefore to be avoided\u2014even if Pyongyang had never acquired the ultimate weapon.<\/p>\n\n\n\n In sum, the deterrent value of nuclear weapons is unproven and in many ways unprovable, ultimately making them a gamble. Macron might place nuclear weapons at the center of French and European security, and Putin might rely on them to scare the West. But in both instances, they are gambling that others will back down over a fear of nuclear weapons\u2019 destructive power. That bet might be correct. But it is a risky one, because it is difficult to know if nuclear weapons are truly an instrument of terror, an instrument of peace through terror or just pointless.<\/p>\n\n\n\n