A House Oversight and Government Reform subcommittee will hold a hearing Wednesday on concerns with the fuel program, including the failure to be able to account for $475 million in 2012.

The audit also questioned whether the fuel program was excessive. It also said that Iranian fuel is less refined than fuel from other sources, and if used to power machines and vehicles provided by the United States and the international community, could lead to premature deterioration of the equipment.

Another major concern was that as the mission in Afghanistan begins to shrink, cash for the fuel program is supposed to expand to an estimated $2.8 billion between now and 2018. The report reflects a fear that without a reliable system in place by the end of 2014 to track the money, it’s unlikely after that point that Afghan government officials will heed American concerns.

A recent United Nations report on corruption in Afghanistan, notes: “While corruption is seen by Afghans as one of the most urgent challenges facing their country, it seems to be increasingly embedded in social practices, with patronage and bribery being an acceptable part of day to day life.”

Ahmad Majidyar, an expert on Iran and Afghanistan at the American Enterprise Institute, a conservative Washington think tank, said that it was difficult to imagine what it would take to stop Afghan officials from buying Iranian fuel, regardless of certification requirements.

He noted that as global sanctions against Iranian oil have intensified, the rogue nation has focused intensely on trade with neighbors, and trade with Afghanistan has increased from $800 million in 2008 to $2.5 billion last year, heading toward an expected $6 billion in the near future. Iranian oil, he said, would have to be a large part of that.

“Iran can’t compensate for their losses in oil sales to China and India with sales to Afghanistan, but Afghanistan is the only alternative they’ve got,” Majidyar said.