In December 2005, as casualties in Iraq steadily rose and domestic support declined, Congressman Frank Wolf (R-VA) called CSP President David Abshire to discuss the establishment of a “Fresh Eyes on Iraq” Task Force, which evolved into the Iraq Study Group (ISG). In the critical, formative stages of this independent commission, CSP worked with two other non-partisan think tanks – the United States Institute of Peace (USIP) and the Center for Strategic and International Studies (CSIS) – to plan and organize the ISG. They began by recruiting former Secretary of State James A. Baker III and former 9/11 Commission Co-Chair and retired Congressman Lee Hamilton to serve as co-chairs. With USIP providing overall coordination and administration and with the membership of the Baker Institute at Rice University, representatives from each institution met regularly to establish the formal framework for the ISG.

In March of 2006, Senators and Congressmen from both sides of the aisle publicly announced the ISG at a Capitol Hill press conference. In addition to Secretary Baker and Congressman Hamilton, Study Group members include four prominent Democrats – former White House Chief of Staff Leon Panetta, former Presidential Advisor Vernon Jordan, retired Senator Charles Robb (a CSP Trustee), and former Secretary of Defense William Perry – and four prominent Republicans – former Associate Justice Sandra Day O'Connor, retired Senator Alan Simpson, former Attorney General Edwin Meese III (a CSP Trustee), and former CIA Director Robert Gates, who was replaced by former Secretary of State Lawrence Eagleburger after President Bush nominated Gates to be Secretary of Defense in November 2006.

CSP played a critical role in rallying broad bipartisan support from both houses of Congress as the ISG moved into its initial analysis phase. Four Expert Working Groups (EWGs), were formed to provide analysis and research on the political situation within Iraq, the broader regional and international strategic environment, military and security issues, and economic reconstruction and development. EWGs members are among most renowned and respected experts in their fields. Integral to the EWGs, CSP nominated distinguished experts for all EWGs, and CSP staff served as advisors to both the Strategic Environment and the Economic Reconstruction and Development EWGs.

In June of 2006, senior CSP leaders and former Ambassador Gary Matthews of USIP traveled to Europe to consult with allies and to evaluate support for the effort in Iraq. Meeting with senior officials in the British government, the North Atlantic Treaty Organization, and the European Union, CSP reported back to the ISG on these efforts in July 2006. Over the spring and summer, the ISG and members of the EWGs met with President Bush, Vice President Cheney, Secretary Rice, Secretary Rumsfeld, and Chairman of the Joint Chiefs Peter Pace. They also conducted extensive, confidential interviews with current and former government officials, military leaders, diplomats from several nations, and regional experts. In early September, the ISG traveled to Baghdad to meet with Prime Minister Maliki and other senior Iraqi, U.S., and coalition officials. This fall, the ISG moved into the policy phase, with final recommendations to Congress and the White House issued on December 6, 2006.