Make no mistake, the worst terrorist attack on civilized order is yet to come. Tragically, it is not if but when, where, and at what cost. We have already seen, in recent times, mass casualties from nuclear and chemical weapons.

The 14th century Black Plague, which wiped out 30-60 percent of Europe’s population from a natural biological pathogen, serves as a stark reminder of the capacity of microbes to inflict deadly harm, as does the 1918 influenza pandemic that killed an estimated 50-100 million people worldwide. Consider the catastrophic losses that could arise today from biological pathogens designed especially to target crops, livestock, or humans, and engineered to do the most damage.

Just imagine what might happen in the aftermath of the anticipated collapse of Daesh (also known as ISIS, ISIL, Islamic State) in Iraq and subsequently in Syria. Daesh leadership has promised to regain “lost areas,” and its fighters and supporters are orchestrating their deadly attacks in dozens of countries in the Middle East and beyond, including the United States. Since the self-declared “Islamic Caliphate” represents a territorial vision without borders, Daesh is likely to resort, without compunction, to a broad range of biological weapons in battles for regional and global dominance.

In 2016 alone, Daesh operatives planned to contaminate Turkish water sources with bacteria causing tularemia, a potentially fatal human illness; another Daesh-linked plot that involved an anthrax attack in Kenya was foiled by the police; and in Nigeria, the army intercepted poisoned fish allegedly brought into the country by Boko Haram terrorists.

Facing potential biological threats, several European countries have recently focused attention on the looming challenge. The United Kingdom expressed concern that Daesh might weaponize Ebola, Germany hosted an international symposium on protection against biological warfare agents, Italy engaged its scientific community to deal with biological defense, and France performed a nationwide drill to prepare for biological attacks.

The U.S. Government is also concerned with the biothreat, spending billions annually to address it. But federal efforts are incomprehensive and fragmented. A bipartisan Blue Ribbon Study Panel on Biodefense, co-chaired by Senator Joseph Lieberman and Governor Tom Ridge, released a report that identified deficiencies and mapped out actions that the President and Congress should undertake to improve the nation’s capabilities to prevent, deter, and mitigate biological incidents.

Preparatory meetings for the recent 2016 Biological Weapons Convention Review Conference recognized the need for adapting to the increasing risk of bioterrorism from scientific advances such as CRISPR gene-editing technology and emerging infectious diseases such as the Zika virus.

To be sure, the vast background of, knowledge for verification and intelligence gathering within the U.S. government in response to chemical and nuclear terrorism can inform our preparedness for biothreats. Although there are major differences, some of the infrastructure and processes are the same. Also on the international level, the Organization for the Prohibition of Chemical Weapons (OPCW) and the International Atomic Energy Agency (IAEA) have extensive experience in safeguard verification for materials and technology.

For all WMD types – nuclear, chemical, and biological – there are problems that arise in verifying that the technologies involved are being used solely for peaceful purposes. However, the problem is most severe for biological weapons, first, because of the lack of oversight by a verification organization under the 1972 Biological Weapons Convention, and second, because of the depth of peaceful biomedical research and extent of the pharmaceutical industry in many member states, such as India and Iran.

A special feature of biological weapons is the reliance on living organisms, with unique security and strategic challenges that complicate arms control, verification, and intelligence collection. The very large array of pathogens and toxins which exist or could be created increases the difficulty of more organized control.

Yet there is an opportunity for sharing information learned in both the chemical and nuclear sectors. There are commonalities in that bans on chemical and biological weapons apply to all countries, without special privileges for a select few, as with nuclear weapons. Likewise, secrecy inherent in the chemical and pharmaceutical industries sets the possession of chemical or biological weapons apart from nuclear weapons, which require a degree of transparency to advertise deterrence. Transferring what we already know to an effective biological weapon regime is no simple task, however.

Thus, in view of the growing evidence that the Islamic State has already used chemical weapons, including chlorine and sulfur mustard agents in both Iraq and Syria, taking measures to prevent a potential Daesh “Black Plague” attack on the international community is a challenge requiring a concerted effort. It therefore behooves all nations to recall the warning in Shakespeare’s King Lear, “We make guilty of our disasters the sun, the moon, and stars: as if we were villains on necessity; fools by heavenly compulsion…”

Yonah Alexander is the Director of the Inter-University Center for Terrorism Studies and Senior Fellow at Potomac Institute for Policy Studies and Milton Hoenig is a nuclear physicist. They co-authored the book Super Terrorism: Biological, Chemical, and Nuclear.