An internal Pentagon watchdog has released another highly critical audit of a dubious U.S. effort between 2010 and 2014 to foster economic development in Afghanistan, a country without a fully functioning federal government and beleaguered by corruption and political rivalries.

The temporary program, called the Task Force for Business and Stability Operations, was appropriated $823 million by Congress, of which $675 million was spent on projects, many of which were abandoned of left incomplete, because of “safety concerns, lack of sustainable design, and other problems,” according to a report by the Pentagon’s Office of the Special Inspector General for Afghanistan Reconstruction.

The audit, requested by Judiciary Committee Chairman Sen. Chuck Grassley, R-Iowa, and then-Sen. Kelly Ayotte, R-N.H., also found more than half the money spent went for overhead, not directly on projects in Afghanistan.

“From the start, TFBSO’s goals were at odds with its capabilities, and its role within the U.S. reconstruction effort was unclear,” the audit concluded, adding, the “TFBSO did not have the time, resident expertise, or outside support it needed to do everything it set out to do,”

The report found that program’s administrators were in over their heads from the start, laboring under unrealistic expectations that failed to take into account obvious obstacles for conducting business in Afghanistan including local politics, culture, weather and security.

The result was wasted time, effort and money.

In one example cited by SIGAR auditors, the TFBSO obligated $51 million for up to 12 large-scale mining contracts, but vastly overestimated the speed at which the Ministry of Mines and Petroleum could work as well as resistance from other government ministries.

After repeated delays, the Afghan government refused to sign any of these contracts.

“The DOD Principal Deputy Secretary of Defense for Policy expressed skepticism about whether the TFBSO mission of economic development was a proper role for DOD,” the investigators wrote. “We share this skepticism.”

“The findings of this audit are just another example of the Defense Department’s failure to gets its financial house in order,” Grassley said in a statement. “Congress appropriated $823 million for task force projects. Auditors found rock-solid supporting documentation for $435 million, leaving hundreds of millions of dollars unaccounted for. This careless bookkeeping means American taxpayers may never know what happened to the rest of their money.”