Site Content


Navigating the Atlantic Storm through the Dark Winter

Terrorist attacks using biological agents are potentially deadly beyond imagination. In 2001, the dissemination of engineered Anthrax struck panic with American civilians and emergency service responders resulting in exaggerated responses and near-ridiculous actions. Inhalational anthrax is fatal if not treated appropriately, but there is treatment. How would be as population fair if the biological agent was something more devastating than anthrax; an agent with no cure or treatment? Let’s use smallpox as an example.

In June of 2001, the Johns Hopkins Center for Civilian Biodefense Strategies along with the Center for Stategic and International Studies, the Analytic Services Institue for Homeland Defense held a senior-level tabletop exercise that simulated the effects of a covert biological attack on the United States. The dissemination of highly contagious smallpox as an act of terrorism became know as the “Dark Winter” scenario. This one-of-a-kind TTx examined the ability of senior-level policy makers to face the challenges of a bioterrorist attack with outbreaks of highly contagious diseases.

A similar event took place in January, 2005, this time among the international leadership community. Known as Atlantic Storm, this TTx continued on a larger scale from Dark Winter. Atlantic Storm simulated the heads of state and senior international governmental leaders attempting to manage a simultaneous smallpox bioterror attack on Istanbul, Frankfurt, Warsaw, Rotterdam, New York, and Los Angeles.

Both Dark Winter and Atlantic Storm focused on government leadership and ability to manage issues in public health, medical services, diplomacy, domestic response, and critical infrastructure. Both exercises were well developed and planned...they did, however, reached differing results. What follows is a comparison of the tabletop exercises Dark Winter (2001) and Atlantic Storm (2005). Despite commonalities in scenario and biological agent, glaring differences have emerged that leave those studying such material wondering and concerned. The opinions and concerns addressed herein are based upon study of documents, video where available, objective analysis of the scenarios themselves, of course, smallpox.

Comparison of Assumptions
Dark Winter focused on the United States as the only target in a “worst-case” scenario; Atlantic Storm targeted the international community with “best-case” circumstances. This primary difference may prove to be a single most perturbing factor when comparing the two exercises.

Although both scenarios simulated the use of smallpox as the agent with similar methods of dissemination, there were concerning differences in the projected infection rates, death rates, and person-to-person transmission potential. Dark Winter assumed a thirty percent fatality rate while deaths from smallpox were projected at twenty-five percent in Atlantic Storm. Atlantic Storm also assumed that there was residual immunity among the affected population with 300 million doses of vaccine available. Dark Winter was somewhat less optimistic; simulating a CDC stockpile of 15.4 million doses of vaccine and allowing for up to twenty percent of stockpile loss due to contamination or improper use.

Dark Winter hypothesized that 1g of smallpox could generate 100 infections when aerosolized resulting in 3000 first generation cases from 30gms of virus. There is no mention of virus quantity in Atlantic Storm; however, both scenarios disseminate the virus via an aerosolizing device under similar conditions. Dark Winter used 1:10 transmission rate (every one person with smallpox could infect ten others) as compared to Atlantic Storms rate of 1:3. Atlantic Storm also anticipated 1: 0.25 for second to third generation while no mention was made in the Dark Winter scenario of second to third generation transmission. Dark Winter planners integrated herd immunity of twenty percent into the scenario which was not accounted for in Atlantic Storm. I found the following excerpt from the Dark Winter scenario an interesting commentary on person-to-person transmission rate. A sidebar reads:

“…Given the low level of herd immunity to smallpox and the high likelihood of delayed diagnosis and public health intervention, the authors of this exercise used a 1:10 transmission rate for Dark Winter and judged that an exercise that used a lower rate of transmission would be unreasonably optimistic, might result in false planning assumptions, and, therefore, would be irresponsible. The authors of this exercise believe that a 1:10 transmission rate for a smallpox outbreak prior to public-health intervention may, in fact, be a conservative estimate, given that factors that continue to precipitate the emergence and reemergence of naturally occurring infectious diseases (e.g., the globalization of travel and trade, urban crowding, and deteriorating public health infrastructure) [26, 27] can be expected to exacerbate the transmission rate for smallpox in a bioterrorism event…”

In contrast, the Atlantic Storm best-case scenario planned for adequate disease control, compliance with public health “social distancing” (a.k.a. quarantine), available vaccine, higher herd immunity, residual protection granted by prior vaccination, and lower transmission rates. The wide range of transmission rates between the two exercises may account for the differences in total number of smallpox cases and deaths. Dark Winters worst-case predicted 1,000,000 deaths with 3,000,000 infections while the Atlantic Storm exercise predicted 660,000 cases and approximately 495,000 deaths.

Summary: Lessons or Recommendations?
Dark Winter summarized the exercise with a list of lessons and Atlantic Storm used the term recommendations to summarize. Below is a list of lessons from Dark Winter or recommendations from Atlantic Storm that seem to be common to both events despite being conducted years apart. Various excerpts from the text have been added to aid explanation.

  • Leaders are unfamiliar with the character of bioterrorist attacks, available policy options, and their consequences.
  • After a bioterrorist attack, leaders’ decisions would depend on data and expertise from the medical and public health sectors.
  • …they were given more information on locations and numbers of infected people than would likely be available in reality.” Statement concerning the amount of infromation given out in both TTx's.
  • …lack of information, critical for leaders’ situational awareness in Dark Winter, reflects the fact that few systems exist that can provide a rapid flow of the medical and public health information needed in a public health emergency.”
  • …it was difficult to quickly identify the locations of the original attacks…”
  • The lack of sufficient vaccine or drugs to prevent the spread of disease severely limited management options.
  • After a bioterrorist attack, leaders’ decisions would depend on data and expertise from the medical and public health sectors.

    … [This] reflects the fact that few systems exist that can provide a rapid flow of the medical and public health information needed in a public health emergency.”
    “What’s the worst case? To make decisions on how much risk to take…whether to use vaccines, whether to isolate people, whether to quarantine people…I’ve got to know what the worst case is” (Sam Nunn).

  • The lack of sufficient vaccine or drugs to prevent the spread of disease severely limited management options.
  • The US health care system lacks the surge capacity to deal with mass casualties.
  • The numbers of people flooding into hospitals across the country included people with common illnesses who feared they had smallpox and people who were well but worried.”
    “…[the challenges]of distinguishing the sick from the well and rationing scarce resources, combined with shortages of health care staff, who were themselves worried about becoming infected or bringing infection home to their families, imposed a huge burden on the health care system.”
  • To end a disease outbreak after a bioterrorist attack, decision makers will require ongoing expert advice from senior public health and medical leaders.
    “…the imposition of geographic quarantines around affected areas, but the implications of these measures (e.g., interruption of the normal flow of medicines, food and energy supplies, and other critical needs) were not clearly understood at first. In the end, it is not clear whether such draconian measures would have led to a more effective interruption of disease spread.”
    “A complete quarantine would isolate people so that they would not be able to be fed, and they would not have medical [care].…So we can’t have a complete quarantine. We are, in effect, asking the governors to restrict travel from their states that would be nonessential. We can’t slam down the entire society” (Sam Nunn).
  • Federal and state priorities may be unclear, differ, or conflict; authorities may be uncertain; and constitutional issues may arise.

    “My fellow governors are not going to permit you to make our states leper colonies. We’ll determine the nature and extent of the isolation of our citizens…You’re going to say that people can’t gather. That’s not your [the federal government’s] function. (Frank Keating).

    “…worried that it would not be possible to forcibly impose vaccination or travel restrictions on large groups of the population without their general cooperation."

    “The federal government has to have the cooperation from the American people. There is no federal force out there that can require 300,000,000 people to take steps they don’t want to take” (Sam Nunn).

    “…Atlantic Storm showed that even experienced politicians have unrealistic notions of what WHO would be able to deliver in a crisis, given its current budgetary, political, and organizational limits.”

    “In Atlantic Storm, leaders viewed border closings and travel bans as an unattractive option for controlling the spread of disease, but, given the lack of vaccine or any other mechanism to control disease, they were forced to consider these measures.

“…leaders were provided with far more situational awareness than they would have had in a real crisis. They were given the locations and numbers of reported smallpox cases in almost real time, and they were constantly updated as information changed. If this had been a real bioattack or epidemic affecting cities in multiple countries, leaders would have had a great deal of trouble getting even this level of basic information.”

My list of Questions:
In the end it would appear that we are not much closer to answering (or instituting) the questions posed by these two exercises. The results of the two events, despite being years apart, have come to similar end points…without resolution. Since Dark Winter, we have seen the 9-11 attacks, dealt with WNV, witnessed SARS, and begun preparing for H5N1. Yet, these questions continue to be re-invented.

Given the time frame of the two exercises, one being pre-9-11 and the other post-9-11, is there any expectation change in the “post-9-11 mindset”?
Can any correlation be drawn between the expectations of national leaders towards international cooperation and state/local leaders towards cooperation with the Federal government?

Will the American public respond differently to a biological attack that threatens only the United States in contrast to an attack threatening the U.S. as well as other nations?
How will we approach issues of evacuation, quarantine, mandatory vaccination, and loss of freedoms? Will compliance be better or worse based on the events of Katrina?

Can we compare the expectations of FEMA during Katrina to the expectations of the CDC during a biological terrorist attack?

Why are we not closer to resolving the issues mentioned in these exercises? So many of the Atlantic Storm recommendations are strikingly similar to the lessons of Dark Winter that one has to ask if the organizers have even read the Dark Winter scenario!