The under secretary of state for arms control and international security advises the president and the secretary of state concerning policies and actions to enhance U.S. national security, with a special emphasis on reducing the threat of weapons of mass destruction to the United States, our allies, and friends. The under secretary oversees the Bureaus of International Security and Nonproliferation; Political-Military Affairs; and Verification, Compliance, and Implementation. The "T-family" covers a wide range of responsibilities critical to U.S. national security, including, inter alia:

• Preventing the spread of nuclear weapons, with particular emphasis on countering the nuclear weapons programs of Iran and North Korea.

• Implementing and verifying agreements in force.

• Developing new tools, such as the Proliferation Security Initiative and the Global Initiative to Combat Nuclear Terrorism, to deal with today's threats.

• Removing landmines from post-conflict arenas.

• Protecting sensitive U.S. technologies and training other countries to control sensitive technologies.

http://www.state.gov/t