Such changes are at the heart of an expanding internal Pentagon investigation of Centcom, as Central Command is known, where analysts say that supervisors revised conclusions to mask some of the American military’s failures in training Iraqi troops and beating back the Islamic State. The analysts say supervisors were particularly eager to paint a more optimistic picture of America’s role in the conflict than was warranted.

Source: Pentagon Expands Inquiry Into Intelligence on ISIS Surge – The New York Times

“revised conclusions to mask” = lied.