In his memoir, ``The Age of Turbulence: Adventures in a New World,'' the former Federal Reserve chairman skewered President George W. Bush and congressional Republicans. Greenspan asserted that the need for secure oil
supplies from the Middle East was the true rationale for the U.S.-led invasion of Iraq in 2003. "I'm saddened that it is politically inconvenient to acknowledge what everyone knows: The Iraq war is largely about oil," Greenspan wrote in a chapter titled ``The Long-Term Energy Squeeze.''