In an interview with PBS host Charlie Rose, Petraeus warned against putting American troops on the ground in the war-torn country, saying the country "may be a Humpty Dumpty that can't be put back together again ... One doesn't know what the various outcomes could be." [...]

Petraeus said that introducing a large U.S. ground force to establish order in Syria is not "sustainable" and that any force on the ground there supported by the U.S. would have to be made up of moderate Sunni fighters - and there currently aren't enough of those to present an effective opponent to counter the terror group ISIS or the government of dictator Bashar al-Assad, whose forces are backed by the Russian military.

"There are some there. We have been enabling them, supporting them and assisting them for some time," he said of the moderate Sunnis. "Clearly, if we really get behind them and vow to protect them again from Bashar's air force and so on, I think you would see a lot more."

In his comments, Petraeus seemed to be describing a no-fly zone in at least part of the country, which would allow Sunni fighters the freedom to organize without being attacked.