Rebels Move East to take Gaddafi's Hometown

The transcript discusses the movement of Libya's eastern rebels into Gaddafi's tribal heartland, with a focus on the strategic importance of Sirte, Gaddafi's birthplace, as a key target for the rebels.

What does the phrase 'all one way into Gaddafi's tribal heartland' imply about the rebels' movement?

Why is the situation described as essential?