This thesis analyzes the potential effectiveness of preventive war, preventive strikes, and interdiction as tools for the United States to counter the proliferation of weapons of mass destruction (WMD). Examination of these three counterproliferation techniques is important because the George W. Bush administration has given more prominence to military operations to deal with WMD threats. Six historical cases of preventive war, preventive strikes, and interdiction, against adversarial WMD programs are examined to show the conditions that make military options desirable and effective and the issues that make their implementation difficult. These case studies reveal that interdiction and preventive strikes are viable and can be effective under very limited legal, political, and military circumstances. Although the United States successfully conducted a preventive war against Saddam Hussein's Iraq, this strategy is not likely to succeed in the cases of Iran and North Korea.