DEALMAKER: Details of Syria Pact Widen Rift Between John Kerry and Pentagon.

Mr. Carter was among the administration officials who pushed against the agreement on a conference call with the White House last week as Mr. Kerry, joining the argument from a secure facility in Geneva, grew increasingly frustrated. Although President Obama ultimately approved the effort after hours of debate, Pentagon officials remain unconvinced.

On Tuesday at the Pentagon, officials would not even agree that if a cessation of violence in Syria held for seven days — the initial part of the deal — the Defense Department would put in place its part of the agreement on the eighth day: an extraordinary collaboration between the United States and Russia that calls for the American military to share information with Moscow on Islamic State targets in Syria.

“I’m not saying yes or no,” Lt. Gen. Jeffrey L. Harrigian, commander of the United States Air Forces Central Command, told reporters on a video conference call. “It would be premature to say that we’re going to jump right into it.”

Kerry can’t even get the Pentagon to go along with his deals — how is he supposed to get anything but the short end of the stick from the Russians?