Russia’s invasion of Ukraine has not gone as the Kremlin imagined, with its forces bogged down around key cities and the Ukrainian army providing stiff resistance. As its troops grow demoralized and its supplies are exhausted, Russia may turn to more drastic measures to win. In Washington, U.S. national security officials are already meeting and planning for a growing possibility that was once unthinkable: that Russia might use biological and chemical weapons in Ukraine.

After German chlorine gas suffocated masses of British and Canadian troops in 1915 during World War I, such “scientific warfare” horrified the international community and led, ten years later, to the League of Nations’ Geneva Protocol, which prohibits the use of chemical and biological agents in war. This convention largely held up through the wars that followed, although some countries, including the United States and the Soviet Union, continued to develop offensive biological and chemical weapons. U.S. President Richard Nixon stopped that program and renounced the American use of such weapons in 1969, and that ban has held up since then. Others have had less compunction about their use. Iraqi President Saddam Hussein deployed sarin and mustard gas against the Kurdish town of Halabja in 1988, killing thousands. Syrian President Bashar al-Assad reportedly launched more than 300 chemical attacks during the Syrian civil war, leaving thousands (if not hundreds of thousands) dead.

Now, as Russian President Vladimir Putin doubles down on his stalled military adventure in Ukraine, the threat has become acute. However implausible a biological or chemical attack once seemed, the United States and its NATO allies need to game out the worst-case scenarios, take inventory of the resources they have at their collective disposal to deal with biological and chemical attacks, and swiftly bolster those resources. There is no time to lose.


Just a few weeks ago, the notion that Russia might use such weapons in its campaign in Ukraine would have seemed unduly alarmist. That is no longer the case. No doubt following intelligence reports, the White House has quietly assembled a team of national security officials to sketch out responses to any Russian biological or chemical attack. Putin has already placed the nuclear option on the table by setting his nuclear weapons forces on alert. Such brinkmanship makes the use of chemical and biological agents more plausible. Putin’s claim that Ukraine itself intends to bring these internationally banned weapons of mass destruction into the conflict seems like one of his classic acts of projection, suggesting that as the war drags on Russia could initiate false flag operations to do just that.

Russia has had, and very likely continues to have, the capability to produce an extensive supply of offensive chemical and biological weapons, whereas Ukraine has neither the capacity nor the will to do so. From the Soviet era, the Kremlin inherited the know-how for weaponizing anthrax, brucellosis, glanders, Marburg virus, plague, Q fever, tularemia, and smallpox, among other toxic bugs. Soviet scientists even tried to insert the mosquito-borne, brain-attacking Venezuelan equine encephalitis into smallpox vaccines. At least three Soviet-era biowarfare labs remain inaccessible to international inspectors, so extreme experiments of this kind could continue in some form.

Putin seemingly has no compunction about using such agents against his political foes: he ordered the assassination of Alexander Litvinenko, a defector and Putin critic, with radioactive polonium in 2006; poisoned another defector, Sergei Skripal, in 2018; and targeted the opposition leader Alexei Navalny with Novichok nerve agent in 2020. Attacking a civilian population with these weapons would represent a tactical change in scale but not in kind. After all, Russia accepted and at least tacitly supported Assad’s chemical attacks on his own people.

Assad used sarin gas on multiple occasions in 2013, and Moscow could not have helped but notice that the world did little to intervene or stop him despite U.S President Barack Obama’s stated “redline” against the deployment of such weapons. So far in Ukraine, international outrage and sanctions have done little to curb Putin’s penchant for brutality as his forces bomb schools and hospitals. But it will take much more than indignation and economic measures to contend with the very real threat of biological and chemical warfare.


Biological and chemical weapons do what bullets and even bombs cannot; civilians can more easily find shelter from shelling and bombing than they can evade invisible gases or microbes. Putin could resort to these horrific weapons in a bid to break the spirit of the Ukrainians resisting his invasion. Russia can control some of the immediate dangers it might face from using chemical and biological weapons. It could outfit its soldiers with protective equipment, vaccinate them, and provide protective antibiotics in advance of any planned attack. The release of chemical agents, such as sarin, chlorine, phosgene, and mustard gas, and biologic agents that cause anthrax, smallpox, plague, or a novel artificially developed virus, would kill large numbers of civilians and create terror on an international scale. The United States and its NATO allies must make clear that such action will not be tolerated, threatening consequences far more severe than the sanctions already imposed and treating any chemical or biowarfare agents that happen to cross into NATO territories as a provocation to war.

U.S. officials have some experience in dealing with such attacks, but nothing of the potential scale of what could happen in Ukraine. The 2001 anthrax attacks, delivered in letters to prominent politicians and media figures, were extremely limited in scope, resulting in 22 infections and five deaths. Yet they caused widespread fear of further threats and were remarkably expensive to clean up: over $1 billion was spent on decontaminating the Hart Senate Office Building and other congressional, media, and post offices. It took more than two years to reopen Washington’s Brentwood postal sorting facility and more than three years to reopen one in Hamilton, New Jersey, from where some of the letters were believed to have been sent.

An anthrax contamination site as large as a Ukrainian city would become a sprawling no-man’s land.

Governments in the United States and elsewhere are unprepared to respond to a state-sponsored attack on Ukraine. A single anthrax release from a plane or drone could kill many thousands before necessary antibiotics could reach affected populations. And it might be very difficult to find a country that has, and is willing to share, the antibiotics needed in time to prevent deaths, since doing so would deplete that country’s own stockpile and leave it vulnerable to attack. An anthrax contamination site as large as a Ukrainian city would likely just sit as an abandoned sprawling no-man’s land, akin to a bacterial Chernobyl.

In the current conflict, whatever the United States and other countries have in the way of vaccines, antibiotics, antidotes, and gas masks would have to go initially to Ukrainian troops and first responders, leaving little to nothing for the tens of millions of civilians under attack. In a sarin gas attack—such as the one carried out in the Tokyo subway in 1995 by the Aum Shinrikyo doomsday cult or in Assad’s assault 18 years later—responders can use large amounts of water to wash away the chemical. But there is often no access to running water in a battle zone with limited and unreliable electricity.

The deployment of a biological agent that can then be transmitted from human to human would present an even more disastrous scenario. A release of an agent as deadly as smallpox anywhere in the world would be a crime against humanity. It seems unlikely that the Russians would be so criminally reckless as to risk using such a weapon, since the virus could spread out of control back into their country. But if intelligence sources ever detected Russian efforts to vaccinate troops and citizens against smallpox or other biowarfare agents, that would instantly change the equation and could plunge the United States and its allies into an existential confrontation with Russia.


U.S. national security officials are already meeting to prepare for these unthinkable events. The United States and its NATO allies must be ready to act. They must find ways to immediately provide assistance and aid to Ukrainians. They should consider whether NATO needs to draw a redline and, if so, what would be an appropriate response to any Russian use of biological or chemical weapons. Officials will have to weigh the tough choice of whether such a crime against humanity would merit military action against Russia, provoking a wider conflict. Letting Russia get away with such an attack would constitute appeasement, a tactic that generally leads to further disasters. Should Putin feel angry or desperate enough to launch a stealth chemical or biological assault on any of the NATO countries aiding Ukraine—a possibility that seems to become less outlandish by the day—the United States and its allies need to have a plan that can be put into operation immediately. 

Planners will need to grapple with several logistical and strategic problems. The United States and its allies, both in NATO and elsewhere, should collectively undertake a comprehensive global inventory of existing and available vaccines for anthrax, smallpox (a disease that would be truly catastrophic if unleashed), and other likely biological agents; antibiotics and antiviral drugs; and antidotes for chemical weapons. Experts must come to an understanding of which medical countermeasures work best. For example, they need to determine which antibiotic should still be the choice for treating anthrax exposure and if the extremely limited global stocks of smallpox vaccines are still effective. Officials need to figure out how long it would take to produce sufficient quantities of vaccines and medical countermeasures, and where the necessary funding to make them will come from. And individual countries must be prepared to greatly expand their own stocks of vaccines, medicines, and other supplies to help Ukrainians and protect their own populations.

A house on fire in Irpin, Ukraine, March 2022
A house on fire in Irpin, Ukraine, March 2022
Carlos Barria / Reuters

U.S. officials and their allies must be aware of the different needs that would follow from a biological or chemical attack. An infectious attack, such as with anthrax, would not be obvious for days, because the onset of symptoms would be delayed, but would soon overwhelm whatever remains of Ukraine’s hospitals and clinics. A chemical attack would require a more immediate response, one akin to that demanded by the bombing of a building that has left people trapped inside the ruins.

An effective response to either a biological or chemical attack would require swift coordination by multiple countries. Ukraine’s partners would have to distribute vaccines and medical supplies as soon as an attack occurred, which means governments would have to set in place logistical agreements ahead of time and determine how to distribute supplies in war-torn areas.

It remains unclear who should take the lead in any broader response to a Russian biological or chemical attack. The government of Ukraine may not be in the position to respond rapidly and effectively on its own. But if not Ukraine, who? It seems unlikely that the United Nations, where Russia has a veto on the Security Council, could do much in this crisis. That leaves the United States as the most likely and logical coordinator of any response.

Officials must answer a host of other granular questions: Who will be responsible for disease surveillance in the aftermath of an attack? Where will the first responders, physicians, and nurses necessary to respond to such attacks come from? Who will train emergency personnel in Ukraine or headed to Ukraine to recognize a biological attack when virtually no currently practicing physician or nurse has ever seen a case of smallpox or anthrax in the flesh? And, crucially, who will pay for everything? The United States and its allies are already pumping billions of dollars into aid for Ukraine. They should add to that sum sufficient funding to guarantee the requisite medical and humanitarian aid, as well, in the event of biological or chemical warfare. Governments cannot simply will into existence new antibiotics, adequate vaccine stocks, antidotes to nerve gas, and elaborate medical countermeasures.

To paraphrase former U.S. Secretary of Defense Donald Rumsfeld, you go to war with what you have, not what you might want or wish you had at a later time. But what the international community has at present, both in resources and preparations, is utterly inadequate to meet the potential challenge. Officials must think about the unthinkable now, because the costs of doing otherwise will be far higher.

Correction Appended (March 25, 2022)

An earlier version of this essay neglected to mention that, in 1969, the United States reaffirmed its commitment not to use chemical weapons and renounced biological weapons. The piece has been amended to include this detail.

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  • MICHAEL T. OSTERHOLM is Regents Professor and Director of the Center for Infectious Disease Research and Policy at the University of Minnesota.
  • MARK OLSHAKER is a writer and documentary filmmaker.
  • They are the authors of Deadliest Enemy: Our War Against Killer Germs.
  • More By Michael T. Osterholm
  • More By Mark Olshaker