WASHINGTON, April 18 (UPI) -- The war in Iraq is "a major debacle" but the buildup of U.S. forces has improved security, a report by the Pentagon's top military educational institute found.

The report, released Thursday by the National Defense University, also concluded that the outcome of the war "is in doubt," McClatchy Newspapers reported.

The report was written last fall by former Pentagon official Joseph Collins, based in part on interviews with other former defense and intelligence officials who were involved in planning the March 2003 invasion of Iraq, McClatchy said. It was published by the National Defense University's National Institute for Strategic Studies, a Defense Department research center.

"Measured in blood and treasure, the war in Iraq has achieved the status of a major war and a major debacle," the report says. "No one as yet has calculated the costs of long-term veterans' benefits or the total impact on service personnel and materiel."

The report concludes that the United States' standing in the world has been seriously diminished and that the war has put a severe strain on U.S. armed forces, McClatchy said.