A Deterrence by Denial Strategy for Addressing Biological Weapons

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Washington’s political failures have loomed large in coverage of the COVID-19 crisis. What’s more, a number of analysts have warned that, after watching these failures play out, hostile powers might take a new interest in using biological weapons to target the United States. This risk is real. Fortunately, the pandemic has also brought into use cutting-edge technologies that can help counter it.

Defending against biological attacks with a strategy of deterrence by denial is now more possible than ever before. Such a strategy would involve developing robust capabilities to prevent biological weapons from causing mass damage, essentially deterring their use by preventing them from having the effect that attackers intend.



Ultimately, a strategy of deterrence by denial will only be credible in the right political environment — one in which Americans and their leaders are united in confronting biological threats. But the sooner Washington begins working toward this goal at the technical level, the sooner it can become a reality. As the government prepares its new national biodefense strategy, the Pentagon should embrace its role in rendering mass-effect biological attacks so ineffective as to be futile.

Technological Change 

Though never formally articulated, deterrence by denial has been in the background of U.S. efforts to address biological weapons threats for several decades. After concerted science and technology investments, the components of a system to effectively recognize and quash future outbreaks were on display during the COVID-19 pandemic. Imperfect implementation in the midst of a major crisis should not be allowed to obscure their revolutionary potential.

In recent years, U.S. defense strategy has increasingly focused on how military forces can continue to operate if attacked with biological weapons. This strategy is reflected in the current orientation of the Pentagon’s Chemical Biological Defense Program. Its mission is to “[a]nticipate future threats and deliver capabilities that enable the Joint Force to fight and win in CB-contested environments.” A strategy of deterrence by denial would go one step further, taking defense and preparedness to the point that they would dissuade adversaries from developing and using biological weapons in the first place.

The first thing needed for deterrence by denial to work is early warning that a concerning biological agent has been introduced. This requires the ability to quickly characterize a pathogen and engage in real-time monitoring of its behavior. Next-generation genomic sequencing, enhanced by machine learning and AI, is now making this realistic. Notably, the U.S. Department of Defense’s capacity-building with partners around the world, including in the realm of genomic surveillance, helped in identifying the first case of COVID-19 outside of China. These partnerships also supported responses in countries like Georgia and South Korea. Thanks in part to Pentagon assets, many components of a global early warning system are already in place, and there is increasing international support for cooperation to bring these components together.

Early warning and genetic sequencing will facilitate the rapid deployment of diagnostic tests and countermeasures. South Korea excelled in this with its rapid COVID-19 diagnostics production, developing one test in just two weeks. In a military context, such rapid responses would include monitoring potentially affected personnel, administering known prophylaxis, and keeping personnel on base until more details are known and protective measures are enacted.

Operation Warp Speed also produced vaccine and medication candidates in record time. One vaccine candidate was produced and sent for clinical trials in just over a month. Discovery, testing, and approval then took about 11 months, much shorter than the usual 10+ years. This proved the game-changing nature of platform technologies in which common production mechanisms can serve as the foundation for the rapid development of countermeasures to specific pathogens. One example is the mRNA vaccine platform, which the Defense Advanced Research Projects Agency had long supported. Its first-ever large-scale use for COVID-19 vaccine development indicated techniques for speeding up and scaling out the process even further — work that is already underway.

Of course, different disease threats require different responses. Bacillus anthracis, for example, is not contagious. Yet it is highly deadly, and so a large-scale attack that spreads it across a large population could kill millions. This risk can be mitigated significantly with sufficient pre-deployed protection and antibiotics, protocols for using them quickly, and widespread vaccinations. The denial of intended catastrophic effects and the risk of retaliation should form a strong disincentive. More transmissible diseases like Ebola are also concerning, particularly as their endemic nature in some regions could help mask their deliberate use as a weapon. The Department of Defense has invested in developing vaccines and fast diagnostics for this scenario, as well as field labs and innovative transport units to tackle the disease in the field.

Deterrence by denial would need to account for a broad range of pathogens by using a broad range of cutting-edge tools. This includes measures like the advanced personal protective gear the Pentagon is already investing in, and persistent genomic sequencing that could identify pre-symptomatic signals through novel techniques like wastewater monitoring on ships, at military bases, or around major cities. 

Funding Deterrence by Denial

The administration should begin to enshrine deterrence by denial for biological weapons in U.S. strategies and plans, including the ongoing biodefense posture review and forthcoming national defense strategy update. Deterrence must then extend down into the mission statements and directives for key defense programs such as the Chemical Biological Defense Program, along with budget adjustments that reflect the shift to a bolder strategy. Implementing a deterrence by denial posture against biological weapons will not require the creation of significant new programs, but it will require reversing the budget cuts these programs have experienced over recent years.

The Biden White House appears to recognize this need. Its April 2021 guidance instructed the Department of Defense to prioritize “biological threat reduction in cooperation with global partners, emerging infectious disease surveillance, biosafety and biosecurity, and medical countermeasure research and development.” However, the Department’s first budget under this administration cut its keystone partnership program — the Biological Threat Reduction Program — by nearly 45 percent. The Pentagon should restore these programs to their prior, higher funding levels starting in its next budget.

The Chemical Biological Defense Program’s work will be central. It develops cutting-edge detection and diagnostic tools, advanced protective equipment, and vaccines and treatments for diseases that carry traits that would make them attractive to weaponize. The program also helps to harden these tools and make sure private sector innovations are suited for conflict environments. Additionally, the program works with international counterparts to understand biological threats and collaborate on defensive strategies. Deterrence should be clearly articulated as the aim of this work, and its leaders must ensure it remains ambitious in terms of innovation and continues collaborating with other agencies as it did during Operation Warp Speed.

Further Steps

Deterrence by denial requires reviving and strengthening collaboration with key allies and partners. In the past, Pentagon efforts reflected this approach even if it was not fully articulated. Between 2011 and 2015, the United States and the Republic of Korea conducted the Able Response biodefense exercises in order to test and improve their capacity to respond to a North Korean biological attack. The aim wasn’t just to protect people — it was to show a sufficiently strong response to make Pyongyang question the value of launching an attack. The world witnessed the benefits of this collaboration in South Korea’s successful early response to COVID-19. The Department of Defense should hold more exercises like Able Response, but tailor them to continue improving on the technological advances made during the COVID-19 pandemic. This includes exercises that focus on early detection, diagnostic development, and countermeasure deployment.

Shifting to a strategy of deterrence by denial could also help defense leaders articulate to their forces the full importance of medical countermeasures like vaccines. In an August 2021 memo regarding the COVID-19 vaccine mandate for defense personnel, Chairman of the Joint Chiefs Mark Milley hand-wrote, “Getting vaccinated against COVID-19 is a key force protection and readiness issue.” While this is certainly true, the language of deterrence would help to convey the military’s tradition of using vaccinations as a critical tool against threats like smallpox and anthrax. The United States developed vaccines against these diseases knowing that nations like the Soviet Union had experimented with them and, for some pathogens, developed vast quantities to use in warfare. The aim was to deny such biological weapons their effect in order to dissuade actors from using them — not just to protect defense forces in an attack.

More broadly, national leaders should view the bioeconomy as the strategic asset that it is. Former Deputy Secretary of Defense Robert Work has argued for “incorporating synthetic biology into the U.S. national security and defense toolkit.” Embedded in this bioeconomy are important biodefense capabilities ranging from skilled personnel to advanced manufacturing facilities. Maintaining this ecosystem and better integrating it into the security community will help ensure the continuation of the technological progress America benefited from in the last pandemic.

Finally, the United States should end its policy of using nuclear weapons to deter strategic-level biological weapons activities. It is not only risky, but also less likely to be effective than deterring biological attacks by denying their intended impacts. This change can be achieved if the ongoing Nuclear Posture Review embraces President Biden’s prior view that the sole purpose of nuclear weapons should be to deter nuclear attacks and to respond to them if necessary.


National security leaders should make it clear that the tools now exist to stop biological threats more effectively than ever, and that America intends to use them. They should also invest in the research and programs that will make this claim credible.

Articulating a strategy of deterrence by denial would help combine all the assets on display during the pandemic into a coherent, easy to understand vision. It would also demonstrate how specific activities — such as preventing access to bioweapons-potential materials, increasing rapid medical countermeasure development capabilities, strengthening biosafety and biosecurity practices, and planning and exercising combined military and civilian responses to biological attacks with allies and partners — can operate together to keep the country safe. Moreover, articulating this strategy might also inspire America’s allies to consider whether their governments are well positioned to adopt it.

At the start of the COVID-19 pandemic, America had many of the capabilities required for effective responses. Due to significant political challenges, among other factors, Washington stumbled in its first attempt to use them. Now the government can use the lessons of COVID-19 to do better. The United States needs to leverage the technological edge embedded in its bioeconomy, take full advantage of the Pentagon’s strong assets for addressing biological threats, and form a coherent strategy centered on blunting mass-casualty biological attacks.

Deterrence by denial is achievable, but not simple. Alternatively, if the nation chooses to perpetuate the problems that led to the death of more than 650,000 Americans in less than two years, we can expect adversaries to continue contemplating how to exploit them.



Christine Parthemore is the chief executive officer of the Council on Strategic Risks, where she also leads the Janne E. Nolan Center on Strategic Weapons. She was formerly senior advisor to the Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs. 

Andy Weber is a senior fellow at the Council on Strategic Risks. His decades of U.S. government service included five-and-a-half years as the Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs.  Follow him on twitter @AndyWeberNCB

Image: U.S. National Guard (Photo by Master Sgt. Becky Vanshur)