As the world reflects on the fifth anniversary of September 11, the prospect of another catastrophe looms. From the explosion of a nuclear weapon in a major city to a pandemic that could kill millions, potential disasters inspire fear from citizens and political action in the name of preparedness.

But our perceptions are sometimes amorphous, uninformed fears of the worst-case scenario. And the policy response – as exemplified by widespread reports of inadequate US preparedness for an Avian flu pandemic – sometimes offers more posturing than prevention. What catastrophes might we witness that we have yet to imagine? What approaches can help states manage disaster, whether or not forecasting proves accurate?

This symposium provides first a general framework for preventing and managing potential catastrophes through risk assessment and action by international organizations. It then attempts to identify some transnational threats that could occur in the next 10 years. The aim is not to alarm but to inform. Nonetheless, this information may be alarming.

The threats we have chosen to discuss are particularly problematic because of their complexity and transnational quality. Nuclear material used in an attack against Paris may be created in one state, turned into weapon with technology provided by another state, and transported and detonated by a global terrorist network. A Saudi oil supply shock would reverberate in petroleum-dependent societies from Canada to Malaysia. Catastrophes with global consequences must be prevented, but no state can do the job alone.

To fill out policymakers’ disaster management tool kit, we begin our symposium with professor and former UN disaster relief coordinator Randolph Kent, who argues that the United Nations must change its fundamental assumptions about disaster management but still offers the best hope for coordinated action. Professor Howard Kunreuther, an expert in risk management, discusses another vital area of intergovernmental coordination: properly assessing risk and adopting security strategies that acknowledge interdependence.

Then we identify three potential catastrophes that could occur within the next decade. Michael Vatis, executive director of the Task Force on National Security in the Information Age, explains the vulnerability of cyberspace to massive attack, costing lives as well as money, by something with nothing other than a laptop. Matthew Simmons, oil expert and chairman of energy investment banking firm Simmons and Company, argues that after ignoring warning signs for decades, the world is on the verge of a serious oil supply crisis whose disruptiveness could rival that of a major war. Finally, professor Graham Allison explores the frighteningly simple possibility of nuclear terrorism, calling governments to cooperate to secure nuclear material.

Only by envisioning these crises, we believe, can citizens became aware of potential dangers and policymakers be impelled to coordinated action. The most complex and destructive threats of tomorrow demand attention today.