A nuclear threshold state is one that could quickly operationalize its "peaceful" nuclear program into one capable of producing a nuclear weapon. This book compares two known threshold states, Japan and Brazil, with Iran to determine if the Islamic Republic could also be labeled a threshold state. Furthermore, it highlights the implications such a status could have on U.S. nonproliferation policy. Although Iran's nuclear program is mired in controversy, it relates to those of Japan and Brazil. While not maintaining as robust of a program and often conflicting with the international community, Iran has the capabilities to produce weapons grade material and could be considered a nuclear threshold state. Dozens of countries in the world have similar nuclear capabilities and maintain the Nuclear Non-Proliferation Treaty rights to advance their nuclear programs so long as they are peacefully applied. Unfortunately for nonproliferation advocates, these capabilities make fuel for both energy and weapons. To prevent proliferation and eliminate the world's nuclear weapons arsenal, the United States will need to alter its policy and convince the world that nuclear weapons should be abolished. Although this task includes a multitude of variables, incremental steps can be taken toward the administration's final goal.