Rebels sever Qaddafi's main supply route. The beginning of the end?

If rebels can hold on to Zawiyah, a recently captured town on Muammar Qaddafi's main supply route from Tunisia to Tripoli, the end of his rule becomes a matter of when, not if.

Libya's rebels won perhaps one of their most important military victories of the country's six-month conflict yesterday, taking the town of Zawiyah west of Tripoli and severing the main route to Tunisia that Muammar Qaddafi has been relying on to keep Tripoli supplied.

When the rebel victory came over the weekend, it clearly took the Qaddafi regime, largely holed up in Tripoli, by surprise. On Saturday, a government bus taking escorted journalists from Tunisia to the capital, where foreign reporters are only allowed to operate under the close watch of regime minders, came under fire near Zawiyah and was forced back. A CNN photographer on the bus reported large numbers of armed men along the road in the Zawiyah area and a stream of civilian cars heading west. After a chaotic and frightening 20 minutes, the bus managed to turn back West and the invited reporters were taken back across the border to Tunisia.

By Sunday, the rebels appeared to have consolidated their victory at Zawiyah and were also advancing closer to Tripoli from the east of the city, based out of Misurata. The gains have prompted a flurry of rumors about Qaddafi seeking an exit strategy and accelerated talks with rebel representatives. While it doesn't appear that a negotiated end to the fighting is at hand – and Qaddafi was his usual defiant and threatening self in an audiotape broadcast yesterday – if his forces can't open a route between the capital and Tunisia, the end of his rule becomes a matter of when, not if.

Yesterday, Qaddafi called on all Libyans to take up arms and reclaim the country "inch by inch" against the traitors. But it's been all one-way traffic lately, and not in his favor.

In addition, something diplomatic is clearly afoot. AFP reports that the UN special envoy on Libya, former Jordanian foreign minister Abdul Ilah al-Khatib, flew into Tunis for what he said were talks on Libya's future. AFP said Mr. Khatib would hold talks with regime officials and rebel representatives. While UN Secretary General Ban Ki-Moon has insisted that a negotiated end to the war is "the only viable means to achieving peace and security in Libya," the rebels are in no mood for compromise at the moment, with Qaddafi seemingly caught in a vice.

Qaddafi's steady loss of territory is making his defeat look inevitable, but it's hard to say how long he can hold out in Tripoli. To answer that question, you'd have to know precisely how much fuel, food, and ammunition he's got stockpiled. Some mind-reading skills or excellent intelligence would also be in order. While Qaddafi, his sons, and his closest aides have little to lose by fighting on, the same could not be said for second-tier regime figures. Will they be pushed to cut deals behind Qaddafi's back by the fear that it will be too late for them to secure their own futures if Tripoli falls to the rebels?

Lack of knowledge on those factors creates a situation where the fall of Tripoli could be days away. Or, it could be months away. What's certain is that the rebels' Western offensive has been a raging success in the past few weeks, and Qaddafi's long-term prospects are growing darker.

Today, there were strong indications of a high-level defection from Qaddafi. The New York Times reports, citing Egyptian security at the Cairo airport, that Libyan Interior minister Nassr al-Mabrouk Abdullah landed in Cairo today on a civilian flight from Tunisia with his family in tow. Qaddafi has sent officials abroad on diplomatic efforts in recent months, but almost always without their families. If Mr. Abdullah, responsible for internal security, has indeed defected, he would be the latest in a string of high-level loses for Qaddafi.

Qaddafi's last interior minister, Gen. Abdel Fateh Younes, defected at the start of the uprising in February (and was murdered near Benghazi a few weeks ago in what appeared to be a case of rebel infighting). Moussa Kussa, his long-time intelligence chief, defected the following month. Such defections can create a momentum of their own, since officials left behind will feel increasingly isolated, and worrying that others are cutting deals to survive and, perhaps, leaving them facing recriminations for the bloody fight back against what started as a peaceful protest demanding democratic change.

The next 48 hours will show whether a decisive blow has been struck at Zawiyah. In the past, rebels have taken ground only to be pushed back with ease. But the increasingly seasoned rebel fighters, enabled by NATO air strikes, have gone from strength to strength, with evidence of real command and control and strategic thinking. Whatever reserve forces Qaddafi has will be badly exposed to NATO air supremacy if rushed to Zawiyah, and his dwindling number of loyalists and military equipment means any shift west, could leave him vulnerable to further advances from Misurata in the east.

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