ANALYSIS-NATO counts on Tripoli uprising to break deadlock
At the same time, there are signs that the security forces on which Gaddafi relies to control internal dissent -- known to Libyans as the "Katiba" -- are being stretched.
Some media reports say that barely-trained students have been given guns and told to man checkpoints in Tripoli because the regular forces have been sent away to the front lines.
However, the balance of forces in Tripoli remains on Gaddafi's side. He still has forces with sufficient numbers, weapons and loyalty to shoot at anyone trying to revolt.
To change that, analysts say, will take a big rebel victory in the east, the defection of an important security unit in Tripoli, or something else which loosens Gaddafi's grip on power in the city.
As with the other approaches NATO has tried to topple Gaddafi, encouraging an uprising in Tripoli will take what the alliance can least afford: time.
"I think there is dissent in Tripoli, bubbling, really percolating grievances," said Joshi at the Royal United Services Institute. "As for whether it (a revolt) is likely I think yes, but not any time soon."
(Editing by Mark John and Mark Heinrich)
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