2001 WMD Terrorism Chronology

Adam Dolnik
Jason Pate
September 18, 2002

In contrast to previous years the scope of the database now is limited to coverage of politically or ideologically motivated cases, along with criminal cases involving exceptionally interesting warfare agents. As part of an effort to develop a more specialized yet robust set of data, incidents involving tear gas have been excluded, as were cases involving syringes filled with HIV-infected blood, the use of poison arrows and spears in the context of tribal warfare, and the possession of cyanide “suicide-capsules” by groups in South Asia. It is from this updated version of the database that the WMD terrorism trend analyses for the 2001 have been derived.[1] The changes in criteria for inclusion are factors responsible for the differences in statistical data published in past reports. In order to account for these changes, the 2001 chronology includes only politically and ideologically motivated cases; statistics for 1999 and 2000 have been updated appropriately for comparison.

It should be emphasized that since the database includes solely open source material, certain shortcomings are inevitably present. In many cases, local media coverage of events is sporadic and dependent on the influx of national and international news stories. For example, many of the hundreds of anthrax hoaxes in fall 2001 may not have been reported in the media. A further problem with open-source information collection involves insufficient coverage of international incidents, where the scarcity of accessible local media sources and Internet web sites would result in the omission of local incidents.

Another possible shortcoming pertains to the representativeness of the data. Since the annual total of CBRN terrorist incidents is very low, even a small increase or decrease in the number of cases appears to be a significant trend shift, even though in absolute terms it is not. For example, the statement that nuclear incidents have doubled in 2001 might sound alarming, but in absolute terms this change involves an increase of only two cases. A further problem is associated with the difficulty of predicting future events based on historical data. The fact that CBRN materials have so far not been used by terrorists to bring about a mass-fatality event does not necessarily preclude the possibility of such an event occurring tomorrow.

From the perspective of WMD terrorism studies, the year 2001 was unprecedented. The mass-casualty attacks of 9-11 demonstrated a willingness of some terrorists to indiscriminately kill large numbers of people to achieve their objectives. The subsequent attacks that utilized letters filled with Bacillus anthracis spores (which causes anthrax) marked the first time a classical biological warfare (BW) agent was successfully used, although crudely disseminated, against a civilian population, possibly by a non-state entity. However, empirical data for the year 2001 does not suggest that a mass-casualty CBRN terrorist attack is more likely in the near future than in the past.

Box 1: Incidents Per Year

Year Number of Incidents (Hoaxes) TOTAL
1999 25 (49) 74
2000 48 (25) 73
2001 25 (603) 628

During 2001, CBWNP staff reviewed over 120,500 open-source reports and selected 585 of them for further evaluation.

The number of incidents for 2001 seems to have increased rapidly in comparison to previous years, but this is largely the result of an astonishing number of anthrax hoaxes following the anthrax-laden letter attacks of fall 2001. The number of hoaxes has risen rapidly, from 49 and 25 in 1999 and 2000, respectively, to at least 603 in 2001. On the other hand, the number of uses, possessions, attempted acquisitions, plots and threats with possession has actually decreased, from 50 in 2000 to only 25 in 2001.

Box 2: Uses, Possessions, Attempted Acquisitions,
Plots and Threats with Possession By Region

Region 2000 2001
United States / Canada 7 7
Asia 16 5
Europe 3 5
Middle East & North Africa 11 1
Latin America 0 2
Russia & NIS 7 3
Sub-Saharan Africa 2 0
Australia & Oceania 1 2
Worldwide 1 0
TOTAL 48 25

Box 3: Hoaxes By Region

Region 2000 2001
United States / Canada 22 566
Asia 0 7
Europe 0 11
Middle East & North Africa 0 4
Latin America 0 5
Russia & NIS 3 3
Sub-Saharan Africa 0 1
Australia & Oceania 0 6
Worldwide 0 0
TOTAL 25 603

Geographical Distribution

Since 1998, most hoaxes have occurred in the United States. This trend continued in 2001, as the term “anthrax” became a household name after the media focus on the anthrax-laden letter attacks. The intense publicity surrounding these attacks clearly inspired a new wave of anthrax hoaxes, both in the United States and abroad.

The overall number of uses, possessions, attempted acquisitions, plots, and threats with possession of agent remained very low in 2001, with most of them having taken place in the U.S./Canada region. Noteworthy in this category are the decreases in the number of CBRN incidents in Asia (from 16 in 2000 to five in 2001) and the Middle East (from 11 in 2000 to only one in 2001). Even though these two regions are considered to be the “hotbeds” of conventional terrorism, the same certainly cannot be said in the context of CBRN terrorism. In fact even the one use of a putative CBRN agent in the Middle East was merely the inclusion of a pesticide in a suicide bomb, in which the explosion consumed the chemical. Such an incident would hardly qualify as a successful CBRN attack.

Box 4: Incident By Type of Event

Event 2000 2001
Use of Agent 35
(6 United States)
(7 United States/
4 Vietnam/
1 Australia/
1 New Zealand/
1 Israel)
Possession 6 2
Attempted Acquisition 2 1
Plot Only 4 6
Threat With Posession 1 1
Threat With Posession 25
(22 United States)
(561 United States)

Type of Event

The number of uses of CBRN agents has decreased dramatically from 35 in 2000 to only 14 in 2001. The numbers in all the other categories in this table are too small to draw any robust conclusions. Whether the one crude use of anthrax spores in letters represents an isolated set of cases or whether it signals a significant change in WMD terrorism trends remains to be seen.


Agent Number of Incidents (Hoaxes)
2000 2001
Biological  26 (22)  607 (600)
Chemical 24 (0) 12 (1)
Nuclear 2 (0) 4 (2)
Radiological 17 (3) 2 (0)
Combination 0 (0) 3 (0)
Unknown  4 (0) 0 (0)
TOTAL  75 (25)  628 (603)

Type of Agent

The anthrax-laden letters represented the only actual uses of biological agents; all other biological cases were hoaxes. Chemicals on the other hand, were the agents of choice for actual “users” while remaining unpopular for “pranksters.” It is not surprising that in almost all hoaxes, alleged biological substances were the agents of choice, because they are easily and safely handled by the impostor while creating difficult problems for responders in terms of identification and determining the level of threat posed by the substance used in a hoax. Conversely, many common toxic chemical agents are easy to procure and use, making them preferable for actual employment.

Radiological agents were involved in only two instances. One was the discovery of a container filled with two kilograms of a “radioactive substance” in Shali, Chechnya, and the other was an unconfirmed plot to attack the Hahn Meitner Institute for Nuclear Research (HMI) in Zehlendorf, Germany.

There were two nuclear cases; neither of a serious nature. The first involved the seizure of five grams of highly enriched uranium in Paris, while the second was a report from the Russian Defense Ministry that terrorist groups had twice been caught “casing Russian weapons-storage facilities.” Also included in this category were two hoaxes, consisting of a false report that terrorists conspired to detonate a 10-kiloton nuclear bomb in New York and a threat by a psychologically unstable prison inmate to blow up the White House with a nuclear bomb.

Box 6: Agents Used

Agent 2000 2001
Acid 8 4
Anthrax Bacteria 0 7
Arsenic 1 0
Cyanide 0 1
Hydrogen Cyanide 1 0
Influenza 1 0
Iodine-125 1 0
Mice poison and wood varnish 1 0
Monazite 10 0
Neuroparalytic poison or toxin 1 0
Poison gas 0 1
Salmonella bacteria 1 0
Sewer water 1 0
Uranium 1 0
Unknown 8 2
TOTAL 35 15

Agents Used

With the exception of anthrax bacteria, the use of particular CBRN agents in 2001 declined or remained relatively constant in comparison with 2000. Other than the anthrax-laden letters, all uses remained at the level of agents that lacked the potential to inflict mass casualties. In fact, even the seven uses of anthrax bacteria likely do not represent an attempt by the perpetrator to kill on a large scale; despite the fact that the anthrax bacterium is a potent BW agent, its weaponization in a way that would enable terrorists to inflict mass casualties is much more complex than the crude delivery method demonstrated in the fall of 2001.

Box 7: Agents Possessed

Agent 2000 2001
Anthrax Bacteria 1 0
Chlorine 1 0
Chlorine, ammonia 1 0
Cyanide 1 0
Uranium 235 0 1
Unknown 2 2

Agents Possessed

No significant trend has been identified because the numbers are too small for meaningful analysis.

Box 8: Incidents By Motive Type

Motive 2000 2001
To Protest Treatment of Animals 1 1
To Express Abortion-Related Sentiment 15 550
To Support Other Single-Issue 3 0
To Fulfill Individualized Objective 13 4
To Establish Ethno-Nationalist Sovereignty 16 7
To Act Because of an Ideology/Belief System 16 50
Unknown 9 14

Motive Type

In 2001, the presence of most types of motives decreased with some notable exceptions. In particular, abortion-related incidents rose dramatically, although they all were hoaxes. The number of incidents motivated by ideology/belief system more than tripled in 2001, from 16 to 50 cases. At the same time it should be pointed out that this number includes 32 anthrax hoaxes overseas, the motivations of which are unknown and the motive types of which were deduced based on the nature of the target. If, for example, a letter with a white powder and a message mentioning “anthrax” was sent to a parliamentary assembly building, an ideological motive was assumed even when the perpetrator’s identity and specific motive was unknown.

Box 9: Casualties

Casualties 2000 2001
Fatalities 795 9
Injuries 113 18


The number of both injuries and fatalities resulting from non-state CBRN attacks both decreased significantly in 2001 from previous years. In 2001, nine people died and 18 were injured in CBRN-related incidents. Five of the nine fatalities and 17 of the 18 injuries were the victims of the anthrax-laden letter attacks. The other four fatalities and one injury were Colombian police officers killed and injured by a crude chemical weapon delivered by rudimentary mortar shells made of modified cooking-gas canisters by the Revolutionary Armed Forces of Colombia (FARC).

For the sake of completeness, it is also important to mention that 778 of the 795 fatalities in 2000 occurred in a single incident — the poisoning of members of the doomsday cult Movement for the Restoration of the Ten Commandments of God in Kanungu, Uganda.[2] The impressive decrease in the number of fatalities from terrorist CBRN attacks in 2001 is therefore considerably skewed by this incident.


From the perspective of CBRN terrorism, 2001 was certainly an unprecedented year. The use of anthrax bacteria, albeit with a very crude delivery system, marked the first time a classic military BW agent was actually used by a sub-state group or individual. Further, the subsequent waves of anthrax hoaxes demonstrated how the general fear of biological weapons can be used to drain government resources and cause mass disruption without the necessity of overcoming the technological and psychological obstacles associated with preparing and carrying out an actual biological weapons attack.

The attacks of September 11th could have a significant impact on the future of CBRN terrorism. First, the attacks have clearly demonstrated a lack of restraint on the part of some terrorists to causing mass fatalities. This fact may invalidate the argument that weapons of mass destruction are an unlikely terrorist tool because of their large-scale indiscriminate destructive effect. At the same time, the 9-11 attacks have demonstrated that terrorists do not necessarily need a CBRN weapon in order produce mass fatalities. Alternative weapon systems with the capacity to match the level of lethality caused by some CBRN weapons are accessible to terrorists that are cheaper, more predictable, and less technologically demanding than CBRN weapons.

On a positive note, the massive retaliation by the U.S. and its allies to the 9-11 attacks might also serve as a deterrent against future “superterrorists.” The assertion that when a terrorist group carries out a mass-fatality attack it at the same time threatens its very existence is no longer a speculation. Henceforth, planners of an attack that has the potential to cause mass casualties will probably have to take the affected government’s response into consideration more than ever before.

Also, it is possible that 9-11 and the subsequent anthrax-laden letter attacks are related, in the sense that the first might have served as a stimulus for the second. Some terrorist groups are proactive, while others, especially right-wing domestic groups, are more reactive in nature. It is possible that a large-scale conventional attack by a proactive group, or the affected government’s response to that incident, could provoke a CBRN attack by a second, more reactive group. For example, a mass-casualty attack carried out by a politically motivated terrorist group might be perceived by some millenarian groups as a harbinger of an upcoming apocalypse, thereby precipitating an escalation of violence on the part of the second group in an effort to accelerate the arrival of Armageddon. Alternatively a government’s intensified efforts to prevent future acts of terrorism may be perceived by some domestic far-right terrorist groups as a deliberate conspiracy to take away civil liberties and disarm the population, thereby provoking a violent reaction.

In conclusion, the data presented in this chronology do not by any means suggest a rising level of CBRN terrorist violence in 2001; rather the contrary.

[1] All information cited in this report is based on the records of the Monterey WMD Terrorism Database
[2] Although the Ugandan police confirmed that a “majority” of the deaths in this incident were the result of poisoning, the actual number of these deaths as opposed to deaths due to strangulation, fire, or suicide is unknown. In the absence of consistent information regarding fatalities, the total number of deaths reported, 778, has been assigned for the purposes of the WMD Terrorism Database.

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