Under the Illinois senator's plan, combat brigades would immediately begin withdrawing one or two brigades at a time, with a complete withdrawal by the end of 2008, CNN reported.

"Let me be clear: There is no military solution in Iraq, and there never was. The best way to protect our security and to pressure Iraq's leaders to resolve their civil war is to immediately begin to remove our combat troops," Obama said in his speech. “Not in six months or one year -- now.”

Obama reminded his audience in Clinton, Iowa, that he opposed the war in Iraq "from the beginning."