then joined the Institute for National Strategic Studies at the National Defense University (NDU) as a research professor, founding and leading NDU's Quadrennial Defense Review (QDR) working group. Flournoy then moved to the Center for Strategic and International Studies (CSIS), where she worked as a senior advisor on a range of defense policy and international security issues. In 2002, a year before the US invasion of Iraq, she argued for preemptive strikes by the US against foreign weapons stockpiles. Flournoy told The Washington Post, "In some cases, preemptive strikes against an adversary's [weapons of mass destruction] capabilities may be the best or only option we have to avert a catastrophic attack against the United States." Founder of CNAS (2007) In 2007, Flournoy co-founded the Center for a New American Security (CNAS) with Kurt M. Campbell. She was named CNAS's president. Flournoy and Campbell wrote a 2007 policy paper called "The Inheritance and the Way Forward" that advocated for a US foreign policy "grounded in a common-sense pragmatism rather than ideology". Obama's first term (2009-2012) After the 2008 presidential election, Flournoy was selected as one of the review team leads for the Obama transition at the Department of Defense. On January 8, 2009, President-elect Obama announced that he was nominating her as Under Secretary of Defense for Policy, to serve under Secretary of Defense Robert Gates. When the United States Senate confirmed her nomination on February 9, 2009, she became the highest-ranking woman in the history of the Department of Defense. In 2009, Flournoy told The New York Times that she had spent much of her adult life steeped in the practice of war. "We're trying to recognize that warfare may come in a lot of different flavors in the future," she said. While serving in the Obama administration, Flournoy crafted the administration's policy of counter-insurgency in Afghanistan. She supported the surge of troops in Afghanistan and helped to design the administration's policy in that regard. In 2009, as Under Secretary of Defense for Policy, she also supported a US "civilian surge" in Afghanistan, coupling increased economic aid with at least 400 new counter-insurgency experts, and doubling the US military presence to 68,000 troops by the end of the year. From February 2009 to February 2012, Flournoy was a principal advisor to U.S. Secretaries of Defense Robert Gates and Leon Panetta. On December 12, 2011, Flournoy announced that she would step