The Obama administration is attempting to cast the Iraq war as a triumph of the president's vision for American foreign policy. As a candidate, he promised to bring this war to an end, and as president he's done so. It also conveniently fits into the Obama campaign's general narrative that President Obama inherited problems of Herculean magnitude.
But, in fact, the Iraq war was on a glide path to conclusion at the end of the Bush administration: the increased troop commitment of the surge and its accompanying counterinsurgency tactics had succeeded in breaking the dynamic of insurgent success; it had concluded the Strategic Framework Agreement with Iraq that the Obama administration is now taking such credit for.
What remained to be done when the Obama administration took office was implementing the agreement in ways that strengthened the practices and institutions of democracy in Iraq, incentivized non-sectarian political cooperation, continued confidence-building measures (especially along the Kurdish fault lines), reassured Iraq both of their sovereignty and our continuing involvement, and fostered support for Iraq among U.S. allies in the region.