Mia Bloom responds to Bradley Thayer and Valerie Hudson's Spring 2010 International Security article, "Sex and the Shaheed: Insights from the Life Sciences on Islamic Suicide Terrorism."

Conventional explanations for suicide terrorism, which center on international anarchy, U.S. intervention in Islamic nations, and religious approval for suicide terrorism, do not sufficiently describe this phenomenon. The life sciences offer explanations that explore the influence of high levels of gender differentiation, polygyny, and obstructed Middle Eastern marriage markets on Islamic suicide terrorism. Combining conventional and life sciences explanations offers greater insight into the causes of Islamic suicide terrorism and the motivation of suicide attacks, allowing policymakers to develop better approaches to counter this threat.

We conclude with an exchange of letters between Duncan Bell and Paul MacDonald and the author on the role of evolutionary theory in realist thought.

The authoer posits that egoism and domination, two "critical components of any realist argument in explaining international politics," are the products of evolution. In grounding realism in evolutionary theory, he maintains that he is according realism the scientific legitimacy it has lacked thus far.

Nuclear, biological, and chemical (NBC) weapons delivered covertly by terrorists or hostile governments pose a significant and growing threat to the United States and other countries. Although the threat of NBC attack is widely recognized as a central national security issue, most analysts have assumed that the primary danger is military use by states in war, with traditional military means of delivery. The threat of covert attack has been imprudently neglected.