The United States should create a “deployable reserve” of contracting experts for emergency reconstruction efforts like the one in Iraq and should change federal law to remove the legal straitjackets that have helped slow the effort there, the first official history of the Iraq rebuilding effort has concluded.

The 140-page history, based on dozens of inspections and audits of construction sites, interviews with participants and input from a panel of government, academic and industry officials, recounts a tale of woe as the rebuilding effort stumbled from bureaucratic confusion to problems with security and understaffing.

The New York Times obtained a draft copy of the history, written by the Special Inspector General for Iraq Reconstruction, an independent federal oversight office, in January. But that draft did not contain conclusions or recommendations, and the historical narrative has been filled out somewhat since then as well.

The office of the inspector general, led by Stuart W. Bowen Jr., is releasing the final version of the history to coincide with Mr. Bowen’s appearance before the Senate Committee on Homeland Security and Governmental Affairs on Wednesday.