Several international defense experts said that a recent letter from America's top military leader about the war in Syria revealed a "great power" weary of conflict, cautious on spending and hesitant about overseas engagements.
"Very risk averse" is how Magnus Ranstorp, a security expert at the Swedish National Defence College, described the recent letter to Congress from Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, in which he laid out the U.S. options on Syria.
"This letter reflects the dilemma the United States is facing," Ranstorp said. "After a decade of military action, the American military knows well that it can be no more than part of a real solution."
To try to manage the chaos in Syria – to which the U.S. has taken a largely hands-off military approach, to the dismay of some on Capitol Hill – Dempsey said the U.S. could control chemical weapons, establish buffer zones, serve as military trainers and advisers for the rebels, conduct limited strikes or create a no-fly zone.
He cautioned, however, that no single option would most likely be an end unto itself.
"Once we take action," Dempsey said, "we should be prepared for what comes next. Deeper involvement is hard to avoid."
The expense also would be great, he said, suggesting that a no-fly zone alone might cost $1 billion a month.
"Risks include the loss of U.S. aircraft, which would require us to insert personnel recovery forces," Dempsey wrote. "It may also fail to reduce the violence or shift the momentum because the regime relies overwhelmingly on surface fires – mortars, artillery and missiles."
But several experts questioned his costs and conclusions.
Michael O'Hanlon, a security expert at the Brookings Institution, said Dempsey's numbers "strike me as fairly high, at least once the mission is established."
The last truly large-scale, highly contested no-fly zone conducted primarily by the United States was over the Balkans in 1999, cost $1.775 billion and lasted from March 24 until June 10, according to a report to Congress.
The most recent no-fly zone in which the United States took part, in Libya, ran about $4 billion overall. The U.S. share was about $1 billion. But in the last couple of decades, no-fly zones imposed over Iraq have cost considerably less, such as $88 million in a month.
Anthony Cordesman, a defense and international security expert at the Center for Strategic and International Studies, said: "Does every option really cost a billion dollars a month for an unknown number of months, or at least cost billions? A 'no-fly, no-move' zone covering limited rebel areas from allied bases – backed by clear U.S. threats to respond if Syria escalates – could be far more affordable."
Christopher Harmer, a senior naval analyst with the Institute for the Study of War, said that while Dempsey's estimate of the costs of a no-fly zone over Syria was probably accurate, it would be the wrong mission. He said precision missiles could cripple, if not remove, the Syrian air force in a single night. He said such simple things as taking out runways would be devastating for a state struggling to survive.
He also said Syria appeared to be using training aircraft instead of its numerous jets, which might be a sign that their maintenance had fallen behind. New aircraft can require six hours of maintenance per flight hour. Old Soviet-era jets could require 12 hours for each hour of flight, and there's no evidence that Syria has enough replacement parts to keep its planes airborne.
It may be that it isn't costs, but a bigger issue in Dempsey's letter, that's raising eyebrows around the world, however.
After a decade of adventurism, the physical and mental toll of war appears to have diminished the American belief in military action. That was evident in the July comments of French Foreign Minister Laurent Fabius, who said during a visit to Mexico: "For a long time, we lived in a bipolar world. Then it became unipolar."
He went on to add that the world was now "zero polar," with the failure of any dominant power to act in Syria a prime symptom of that.
Laurence Nardon, a security expert at the Paris-based Institut Francais des Relations Internationales, said it was wrong to see the United States as a diminished military power because its naval superiority alone provided superior strength and influence. But a decade of war appears to have taken its toll.
In an email, she characterized the "general tone" of Dempsey's letter as "very cautious, almost reluctant, about the whole thing. . . . This is not a great power endeavor."
Ranstorp said a swift collapse of Bashar Assad's regime might leave people in charge who weren't to the United States' liking. He compared the war in Syria to "multidimensional chess, played underwater, where the pieces are all moving all the time.
"The letter reflects that complexity, and the very real damned-if-you-do-damned-if you don't reality of Syria."
By Matthew Schofield
McClatchy Washington Bureau