Earlier this month, while on an trip to Latin America to discuss climate change, Defense Secretary Chuck Hagel sat down and wrote a highly private, and very blunt memo to National Security Advisor Susan Rice about U.S. policy toward Syria.
It was a detailed analysis, crafted directly by Hagel "expressing concern about overall Syria strategy," a senior U.S. official tells CNN. The official directly familiar with the contents declined to be named because of the sensitivity of the matter.
The existence of the memo itself was first reported by the New York Times.
Hagel so far has not made his concerns public and is not likely to, according to the official. It comes at a time when the Pentagon is well aware there is growing, but anonymous chatter, that some White House officials are unhappy with Hagel's performance. So far there is no indication the President Barack Obama shares those views.
The focus of the memo was "we need to have a sharper view of what to do about the Assad regime," the official said. The official refused to provide additional details, but did not disagree with the notion that Hagel feels the U.S. is risking its gains in the war against ISIS if adjustments are not made.
Some analysts have pointed out US airstrikes in Syria against ISIS can benefit the Assad regime which also opposes ISIS. Hagel's concerns are not related to the Pentagon effort to train and equip moderate Syrian forces, something he still strong supports the official said.