In a less than a week’s time, disappointment turned into optimism for Libya’s opposition. After months of incremental progress on the ground and hundreds of NATO airstrikes, the North African country’s band of rebels have had an impressive string of victories against Muammar Gaddafi’s struggling army, with cities just a few dozen miles away from the capital now under the transitional council’s umbrella. Gaddafi’s soldiers are battered, rebel commanders say, and increasingly tired of putting their own lives on the line for a regime that is destined to fall this summer.

The rebel capture of Az Zawiyah, strategically located between Gaddafi’s Tripoli and the Tunisian border crossing, has had the intended effect of squeezing the Libyan government’s access to vital resources. Gas to fuel trucks, food to feed the troops and weapons to fight the rebels are all running low. While the Libyan-Tunisian border checkpoint is technically still in the hands of Gaddafi’s men, supplies are unable to reach beyond a third of the way to the capital. Large swaths of the Libyan desert, which until recently were contested, are now mainly held by rebel forces. Absent the occasional loyalist sniper or a few GRAD rockets fired at rebel positions, the opposition has a strong foothold in the western area of the country, starting from the Nafusa Mountains to a mere thirty miles from Tripoli.

By cutting of highways and other roads leading into the north, Libya’s opposition managed to encircle the capital from all directions, depriving the city of the materials that are needed to sustain the battle — all the while limiting Gaddafi’s options.

The news is encouraging for a NATO coalition that has backed the anti-Gaddafi movement to the fullest extent possible short of direct military intervention.

While it is tempting to predict the strongman’s imminent demise, Libya is still prone to a violent showdown. Gaddafi has lost all semblance of credibility in the south, east and west of his country but retains some popular support in Tripoli. Most of his active duty soldiers who were previously defeated along the country’s western frontier have been called to redeploy into the city center, a move that might indicate the regime’s willingness to fight to the last man.

A popular uprising against Gaddafi’s forces in Tripoli before the rebels enter is a possibility, though a distant one at that. The Transitional National Council know that many Tripoli residents are too scared to revolt, having been locked by Gaddafi’s men in a perpetual state of fear throughout the uprising. Tripoli is the one city in Libya that is still fortified by government compounds and patrolled street to street by Gaddafi loyalists. Most of the anti-government demonstrations that surface in the city, however small, are snuffed out.

The TNC also understands that a brazen advance into the capital could be the most violent battle of the entire war. This makes the siege of Tripoli all the more central to the rebels’ battlefield strategy. By isolating the coastal enclave and choking off fuel shipments into neighborhoods, electricity shortages and rising food prices will hopefully annoy some of the more pragmatic Libyans in the capital to join the opposition’s side. However, these developments will be moot unless the rebels actually consolidate their gains, which has been exceedingly difficult as Gaddafi’s soldiers rely on mortar and rocket counterattacks to stall their advances.

The regime is clearly at its weakest since the start of the uprising in February but an embattled Gaddafi could actually transform the Libyan conflict into a more catastrophic one in the short term. A ruler is far less likely to resort to Scud missile attacks if he thinks his authority is relatively secure. But with Gaddafi’s men folding over the last three days to rebel and NATO pressure, the likelihood of the dictator using long range weapons increases. Given Gaddafi’s insistence on fighting rather than surrendering, more Scuds flying around northern Libya may be his final act of desperation.

Everyone hopes that Gaddafi would rather save his skin rather than ruin the country he has governed for the past 42 years. Unfortunately, his past indicates that may be more prone to lashing out than compromising. With the rebels near their doorsteps, the Gaddafi family’s determination is at its peak.