By the time Barack Obama took up residence in the White House in 2009, he was already determined to make nuclear nonproliferation a major plank in his foreign policy agenda, having embraced the "Global Zero" vision of a world without nuclear weapons. The person he chose to launch the United States down that long and difficult path was a nuclear-weapons expert who had spent her career going to school, literally and figuratively, on the Russians. Gottemoeller did not disappoint. As the lead U.S. negotiator, she reached agreement on New START, the pact that limits deployed strategic nuclear warheads in the U.S. and Russian arsenals to 1,550 (down 10 percent from the unverifiable 2002 Moscow Treaty). Not only did Gottemoeller help shepherd New START through a skeptical Senate in 2011, she is also currently talking with the Russians about a follow-on agreement that would cut both countries' arsenals even further. Born in Columbus, Ohio, Gottemoeller, 60, majored in Russian as an undergrad at Georgetown University and went on to earn a master's from George Washington University's Elliott School of International Affairs. She studied the Soviet fishing fleet at the Commerce Department and focused on U.S.-Soviet relations at the Rand think tank. She served on President Clinton's National Security Council as director of Russia, Ukraine, and Eurasia Affairs, with a focus on successfully denuclearizing Belarus, Kazakhstan, and Ukraine after the dissolution of the Soviet Union. Later she rose to deputy undersecretary of Energy for defense nuclear nonproliferation and was director of the Carnegie Moscow Center. Gottemoeller is married to career State Department official Raymond Arnaudo. They have two sons.