An Iraqi works in the garden of Paradise Square in Baghdad, on March 20, 2013, the tenth anniversary of the US-led invasion of Iraq. In his final report to Congress this month, the U.S. Special Inspector General for Iraq Reconstruction, Stuart Bowen, came to the conclusion that the $60 billion the U.S. spent on rebuilding in Iraq produced too few results. - 

The United States has officially been out of Iraq for about 15 months. But there are still thousands of American soldiers stationed in the country today, ten years after the first full day of war. All those people, along with thousands of reconstruction projects and programs that we left behind.

The cost of those projects totaled about $60 billion -- that's a bill footed by the American taxpayer. And that money wasn't exactly well-spent, says Stuart Bowen, the Inspector General for Iraq Reconstruction.

"The United States must act to improve, to reform its approach to stabilization and reconstruction operations," he said. "And we are not well organized, well structured to carry them out, to plan them, for that matter, or to oversee them."

Bowen says one crucial lesson learned was, "don't carry out large infrastructure rebuilding programs until sufficient security is established." He said that for the first five years of reconstruction, much of the rebuilding in Iraq used cash to fund it -- something that contributed to the fraud and waste associated with the program. In addition, Bowen critiques the initial contracts to rebuild, calling them a virtual "open checkbook."

Still, Bowen is optimistic about the future. He's confident Congress is listening to his reports even as other issues, like the sequester, demand their attention. And he says it's important the United States gets better at rebuilding nations like Iraq and Afghanistan.

"There's no doubt that we are going to again face substantial stabilization and reconstruction operations in our future, perhaps in the near future, perhaps in Syria," he says.

Follow Kai Ryssdal at @kairyssdal