Following a string of strategic setbacks, Libyan leader Muammar Qaddafi's days appear to be numbered, Defense Secretary Leon Panetta said today at an event in Washington.  "I think the sense is that Qaddafi's days are numbered," Panetta said on Tuesday at an event at the National Defense University in D.C. alongside Secretary of State Hillary Clinton, according to Reuters. On Monday, Libyan rebels severed a key coastal highway and supply route, and a top official in Qaddafi's government, Nasser al-Mabruk Abdullah, reportedly defected. Referring to the development, Panetta said, "Qaddafi's forces are weakened and this latest defection is another example of how weak they've gotten." Still, Libya's civil war has been replete with statements from both rebels and pro-Qaddafi forces that the opposing side is near defeat and doubts remain about how unified Libya's opposition is.