How did the Long Walls protect Athens during a land invasion?

The Long Walls were a strategic defensive system that connected the city of Athens to its port, Piraeus, creating a secure, enclosed corridor.12

During a land invasion, these walls protected Athens by ensuring that the city remained connected to the sea, even if enemy forces occupied the surrounding countryside of Attica. This allowed Athens to utilize its powerful fleet to import essential food supplies and resources safely, effectively turning the city into an island that could withstand a siege. By maintaining this maritime lifeline, the Athenians could avoid direct land battles against superior infantry forces while sustaining their population and military operations.132