After months of slogging advances and retreats, rebels finally appear poised to strike a decisive blow against the regime of Libyan leader Muammar Gaddafi. The key town of Zawiya, just outside of Tripoli, has been retaken and the rebel army has hoisted the tri-colored flag over the town.

This is startling. The last time I saw Zawiya was from the inside of a van heading to the Tunisian border. I had just been released to the Hungarian embassy after being held by the Gaddafi regime for 44 days.

Video: GlobalPost's James Foley recalls his time in Libyan captivity

As we passed through on May 20, Zawiya appeared to be a pock-marked ghost town devoid of people and bracketed by Gaddafi checkpoints. Green flags were draped along the main avenue.

I had been imprisoned with several young men from Zawiya after the brutal retaking of the town by Gaddafi forces. Walid and Rashid had been considered dangerous enough to be imprisoned for months. Their crime— driving through town. They were two of hundreds of young men scooped up because they were from Zawiya. They had never picked up a gun. Although Rashid used to proclaim he was a doctor of RPGs (Rocket Propelled Grenades), it amounted to messing with a foreign reporter to pass time.

An actual Libyan doctor, who had been helping an Al Jazeera team when Zawiya was surrounded, described tanks firing directly on the people. After fleeing from the hotel to a mosque, the team was captured. He was imprisoned and tortured. His experience ended with a mock execution.

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Zawiya had turned into a very dangerous place.

So if reports are accurate that rebels are now holding Zawiya, this is a significant blow to the regime, and not just a psychological one. Zawiya is positioned on the coastal highway to Tunisia and has the one small refinery the regime was still able to suck some fuel out from. Without access to Zawiya's refinery, Tripoli will be slowly choked of vital food and fuel.

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So, is this the beginning of the end for Gaddafi?

After the huge cost of taking Zawiya and losing it the first time, it appears that thousands of rebel fighters and townspeople are marshaling to prevent that from happening again.

This morning, rebels reported taking control of Garwan, which is the southern gate to Triopoli and there has already been movement to push east toward Gaddafi-held Zliten. With the NATO blocking resupply by the ocean, Tripoli is effectively blocked in and is already suffering.

Benghazi is now in better shape than the once plush capital, according to reports. At the very least the rebel capital is getting a trickle of the embargoed millions and is the recipient of European and Arab loans. But Gaddafi still commands a city of two million that is under a siege and many under the belief that NATO's bombing and the rest of the world's condemnation is a call to rally around their leader.

The question is how long will it take for a wholesale internal military revolt to force Gaddafi's hand.

The feared Khamis brigade, led by Gaddafi's son Khamis, who may or may not be dead, will unlikely ever defect. It is now charged with locking down the capital in the event the rest of the military flips. But there have been many reports that cooperation between African mercenaries and regular Libyan forces has started to unravel. If regular regime soldiers begin deserting wholesale and other Africans begin shooting them, it could be the internal breakdown the rebellious neighborhoods of the capital are waiting for. They'll be ready to spring from inside and the rebels from all sides.

If Gaddafi is negotiating with the rebels in Tunisia, as has been reported, he is likely trying to buy time. He knows that losing Zawiya would be catastrophic and is massing his forces now. Certainly taking Tripoli without huge internal revolt, is almost impossible. This is a paranoid dictator who's planned for a scenario like this for decades. And the "mad dog" as former U.S. President Ronald Reagan called him, announced yesterday, "Get ready for the fight ... The blood of martyrs is fuel for the battlefield."

Gaddafi will not leave with his entourage for South Africa, as yesterday's twitter rumor-mongers, myself included, had hoped. Instead, a top regime official fled to Cairo. But it appears Gaddafi doesn't want to go out like Mubarak or Saddam.