As the Cold War ended and new counterterrorism priorities took root in the 2000s, the threat of nuclear terrorism cemented itself as the ultimate catastrophic scenario. Dick Cheney famously stated shortly after September 11, 2001, “If there was even a [one] percent chance of terrorists getting a weapon of mass destruction, and there has been a small probability of such an occurrence for some time, the United States must now act as if it were a certainty.”
Great care was taken to secure the Soviet Union’s nuclear weapons following the collapse of the state for this very purpose. The Obama administration later held four nuclear security summits to inspire international cooperation for increasing physical security at nuclear facilities. Today, the National Nuclear Security Administration’s (NNSA) Office of Material Management and Minimization leads the effort to convert the fuel in various international civilian reactors from weapons-usable highly enriched uranium (HEU) to less risky low enriched uranium (LEU).
Despite these successes, it remains difficult to definitively discern whether specific action prevented and deterred nuclear terrorism or if other factors are at play for why such an event never materialized. It is a fact that no terrorist group has yet successfully pursued a strategy to develop a nuclear device. Yet, it may very well be the case that no group has ever legitimately tried. Terrorism as a strategy of targeted political violence may be largely incompatible with the consequences of acquiring and detonating an improvised nuclear device.
In 2004, US President George W. Bush received unanimous support from the UN for a resolution calling on countries to enact stronger controls to block terrorists from acquiring biological, chemical, and nuclear weapons. Since then, American policy turned away from the global war on terror and back to the strategic competition found in the Cold War. The fourth International Conference on Nuclear Security (ICONS) held in May 2024 was the first of its kind to conclude without a ministerial declaration. Yet, the risk of nuclear terrorism has arguably not grown despite a shift in national security priorities.
In a 2019 piece written for the Bulletin of Atomic Scientists, authors Christopher McIntosh and Ian Storey argue that there are four main options for a terrorist group that acquires a nuclear weapon: blackmail, opacity, latency, and dormancy. These options fall on a spectrum from overt threats of nuclear use to keeping the existence of a nuclear device a secret until its detonation. In all of these strategies, however, deterring a nuclear attack is possible as the outcome for use is the same: guaranteed massive retaliation from state governments.
As outlined by Keith Payne in a National Institute of Public Policy report, some scholars incorrectly assume that terrorist groups are undeterrable because they are irrational and possess no territory to hold at risk for assured retaliation. Terrorism is a fundamentally local endeavor and maintaining the support from the surrounding populations is key to preserving the cause. A deterrence by punishment scenario therefore also involves inciting local communities to turn on the terrorists they harbor.
Title 22 of the United States Code, Section 2656f(d) defines terrorism as “premeditated, politically motivated violence perpetrated against noncombatant targets by subnational groups or clandestine agents, usually intended to influence an audience.” The key word is “premeditated” and supports the argument that groups employing terrorism are indeed rational actors, with their decisions about organizational structure, monitoring of funds, and selection of recruits providing evidence to support this statement. As with any rational actor, deterrence is possible.
A deterrence-by-denial strategy, although more difficult, is also legitimate. Ensuring states make it as difficult as possible for groups to acquire material aims to deter groups from even trying. Convincing states to do this may then require assured retaliation from other states. Perhaps there is a reason why former Secretary of Defense William Perry’s fears of North Korea selling plutonium to the highest bidder never materialized. For a regime already well-familiar with the international community’s condemnation of its nuclear program, giving others another reason to take out its nuclear facilities by selling material to a group would be strategically unwise.
However, for a nuclear peer of the United States, such as Russia, holding it responsible for lax security is more difficult. In 2011, a Moldovan lawyer was caught attempting to sell HEU on the black market. Forensic analysis confirmed the material very likely originated from Russia. This is not the first time weapon-usable nuclear material has gone missing from Russia. Still, Russia, like any other state, is motivated to prevent nuclear terrorism within its borders; the likeliest place for such an attack to happen is near the facility where material goes missing.
In physicist Michael Levi’s opinion, deterrence credibility is better served with certain attribution following an attack. Going further than assessing a relationship between a state program and a terrorist group, nuclear forensics attempts to identify exactly which country interdicted material originated. At best, a state would be forced to admit poor security practices that led to the theft of material. If used in a terror device, this excuse may not hold up to international scrutiny with any community affected still demanding its pound of flesh.
Neither a strategy of deterrence by punishment or by denial requires the level of explicit policy that was seen in the early 2000s. While not unhelpful, it is rather the continued existence of nuclear-armed states with massive conventional superiority over terror groups that may be the most successful tool in combating the risk of nuclear terrorism. Deterrence against nuclear terrorism, for now, is holding.
Alexis Schlotterback is a Senior Analyst at the National Institute for Deterrence Studies. Views expressed are the author’s own.
About the Author
Alexis Schlotterback
Alexis Schlotterback is an analyst at the National Institute for Deterrence Studies and one of the NIDS Academy Administrators. Her experience includes a Masters from Missouri State’s School of Defense and Strategic Studies and participation in the National Nuclear Security Administration Graduate Fellowship.
