A new commission examining waste and corruption in wartime contracts is getting a grim report from government watchdogs who say poor planning, weak oversight and greed combined to soak U.S. taxpayers and undermine American forces in Iraq and Afghanistan.

Stuart Bowen, the special inspector general for Iraq reconstruction, says U.S. taxpayers have paid nearly $51 billion for a wide array of projects in Iraq — from training the Iraqi army and police to rebuilding the country's oil, electric, justice, health and transportation sectors.

Some of these projects succeeded, Bowen informed the Wartime Contracting Commission at its first public hearing, according to his written testimony, but many did not. Violence in Iraq along with constant friction between U.S. officials in Washington and Baghdad were also major factors that undercut progress.

The U.S. government "was neither prepared for nor able to respond quickly to the ever-changing demands" of stabilizing Iraq and then rebuilding it, Bowen said in his written testimony. "For the last six years we have been on a steep learning curve."

A lengthy study by Bowen's office, "Hard Lessons: The Iraq Reconstruction Experience," reviews the problems in an effort the Bush administration initially thought would cost $2.4 billion.

Overall, the Pentagon, State Department and U.S. Agency for International Development have paid contractors more than $100 billion since 2003 for goods and services to support war operations and rebuilding projects in Iraq and Afghanistan.