What motivates countries to pursue weapons of mass destruction (WMD)? 2 Despite a wave of research over the last several years on the spread of nuclear weapons and the consequences for international security, the spread of chemical and biological weapons (CBWs) remains relatively under-explored. In some ways, this makes sense—the West’s concern with Iran’s WMD development program is not driven by Iran’s chemical or biological weapons programs. Instead, it is Iran’s pursuit of nuclear weapons that propels international concern about the Iranian regime. On the other hand, policy makers worried a great deal about Saddam Hussein’s biological and chemical weapons arsenal before the Gulf War—especially after evidence surfaced of Saddam’s usage of chemical weapons against the Kurdish population in Northern Iraq. As the “poor man’s atomic bomb”, many countries seem to view biological and chemical weapons as the best chance they have, short of nuclear weapons, of developing deadly weapons to protect themselves against their neighbors—or increase their ability to threaten them.