Mr. Hof said in an interview that he wrote the tough criticism because he believes the president needed to act, not go to Congress.
“One of my main themes of writing has been the general disinclination of the national security system in the administration to approach things from the point of view of national security objectives and accompanying strategy,” he said. “In this particular instance, I thought the soundest course of action for the president was to strike, strike hard, and then explain himself to Congress ex post facto.”
Among Syria policy critics, there were none closer to Mr. Obama than Mr. Gates and then Mr. Panetta. As defense secretaries, Mr. Gates guided the president’s policy of opening the ranks to gays, while Mr. Panetta oversaw the NATO bombing of Libya.
“I believe to blow up a bunch of stuff over a couple of days to validate a point or principle is not a strategy,” Mr. Gates said, according to The Associated Press.
“When the president of the United States draws a red line, the credibility of this country is dependent on him backing up his word,” Mr. Panetta said.
But the Obama team is putting some of its trust in Mr. Putin to ensure his client state of Syria gives up its chemical weapons. Russia and the U.S. agreed on a process to have inspectors identify all such weapons, with the Assad regime’s help, and to dispose of them by the end of 2014.
“Others can disagree and that’s fine,” Mr. Carney said. “The president has enormous respect and appreciation for both of his former secretaries of defense.”
He added that their disagreement on the need for airstrikes “only reinforces the fact that these are not easy decisions to make or easy positions to take.”
• Dave Boyer contributed to this report.