Libya conflict: Beginning of the end?
After weeks of military stalemate things do now seem to be moving on the ground in Libya.
Nato claims that anti-Gaddafi forces are "assuming control of the key approaches to Tripoli". The Alliance's military spokesman on Tuesday argued that these advances represent the rebels' "most significant territorial gains for months".
The fighting is now some 40km to 60km (25 to 37 miles) from the Libyan capital.
To the west, forces loyal to the rebels' National Transitional Council (NTC) have advanced on Sorman and Zawiya, two towns on the coastal road leading west from Tripoli towards the Tunisian border.
A little to the south of Tripoli rebel troops are reported to have entered Gharyan.
These advances are of crucial strategic significance. Zawiya is the location of Col Muammar Gaddafi's regime's only functioning oil refinery.
But the good coastal road is also an important route for smuggled fuel coming from Tunisia. In addition to the coastal route, a second supply line runs south through Gharyan and then west to Tunisia.
So if Sorman, Zawiya and Gharyan can be held by Col Gaddafi's opponents then the regime's two vital supply routes to Tunisia will have been cut.
A word of caution, though, is in order. The fighting is far from over. Many of the on-the-ground reports are sketchy.
And up to now the rebel fighters have often shown little military momentum, their advances evaporating almost as quickly as they are made.
But there are grounds for thinking things are changing. For a start pro-Gaddafi forces are under greater pressure on all fronts.
Nato says that Col Gaddafi's troops have been pushed well back from Misrata to the east of Tripoli. There is also reportedly fighting on the outskirts of Brega, between Tripoli and Benghazi.
Nato, of course, has every reason to paint a positive picture of the rebels' gains.
Nonetheless, it is likely that the cumulative impact of the alliance's air power is finally being felt. Recent air attacks have concentrated on command and control sites and areas from which pro-Gaddafi forces have been staging their attacks.
This, with the constant daily attrition of heavy equipment, seems to have significantly tilted the balance.
However the rebels' success raises all sorts of new questions.
If their gains can be consolidated, is this conflict reaching its end game? And if so, how will it end? Will rebel forces move on Tripoli itself or will some kind of deal be done?
Nato governments have been working closely with the NTC on a plan for the immediate aftermath of the conflict.
The lessons from the collapse of the Iraqi regime are still in everyone's minds. They do not want to see the chaos of a power vacuum, revenge killings, looting and so on.
Indeed, the final stages of this conflict pose particular problems for Nato whose formal mandate, remember, remains the defence of Libya's civilian population.
Critics have argued that this is largely a fiction. Nato has waded in on one side in a civil war, they say, and its air operations have effectively served to tilt the balance of power away from Col Gaddafi towards his opponents.
Nato's intervention began with the immediate goal of protecting the people of Benghazi from advancing government forces.
The war could end with Nato having to ensure the safety of civilians in Tripoli as a new regime advances on the city.
This is going to be the real test of the understandings made between Western governments and the rebels and of the trust invested in the NTC by key Western governments like those in Britain and France.