“The regime still vastly overmatches opposition forces militarily,” Gen. Carter F. Ham, the ranking American in the coalition operation, warned in an email message on Monday. “The regime possesses the capability to roll them back very quickly. Coalition air power is the major reason that has not happened.”…

General Ham said there had been some “localized wavering” of government forces, notably in Ajdabiya, to the east, but so far only isolated instances of military or government officials defecting to the opposition. His remarks came after American and European bombs battered the coastal city of Surt — the rebels’ next objective — in Colonel Qaddafi’s tribal homeland on Sunday night, permitting the insurgents to advance toward the city’s doorstep.

But news reports from Surt on Monday said there was no sign of a rebel takeover and the city seemed quiet. Nonetheless, some military vehicles and dozens of civilian cars loaded with personal belongings were seen heading west from Surt toward Tripoli, 225 miles away.

A battle for Surt could help decide the war. Earlier, the rebels had recaptured two important oil refineries and a strategic port within 20 hours.