The United States spent up to $28 million more than it had to on camouflage uniforms for the Afghan National Army because of the sartorial tastes of a single Afghan official, an American government watchdog said on Wednesday.

A report by the Special Inspector General for Afghanistan Reconstruction found that the Pentagon needlessly spent millions to license a proprietary camouflage pattern that replicates lush forests. Most of Afghanistan’s landscape, however, is desert, and the Defense Department owns dozens of similar patterns it could have used free, the report said.

“They picked the pattern based on a fashion preference, not by experts, but by the minister of defense,” said John F. Sopko, the special inspector general. “That was a dumb decision.”

By 2007, six years after the United States and its allies invaded Afghanistan, the ragtag soldiers of the Afghan Army wore a hodgepodge of uniforms. The United States and its allies have spent millions on overhauling and training Afghanistan’s security forces. Purchasing matching uniforms was one expense.