Rhun is an important pivot in Sauron’s future power base. The inhabitants of these lands, the Easterlings, were more than one important part of his force. It is in his influence on Rhûn that the dark lord’s greatest strength is revealed.
The Threat of Rhûn – The Easterlings
There are some opposites that cannot be reconciled. fire and water, cat and mouse, the Easterlings and the free peoples of the West. The inhabitants of Rhûn are through all three ages in conflict with the West.
In the first age they were secretly associated with the apostate valar Melkor. Melkor’s successor Sauron also recruited troops for his armies here. Easterners have a rather primitive culture and will born to fight.
This war-trained elite makes you crucial part of Sauron’s army out and is therefore strategically very important for him. Even in the Third Age at the time of the original Lord of the Rings trilogy, the western races still struggle with them.
Sauron: The master of manipulation
In the literary reference, Sauron gives one of his rings of power Khamul, a king of the Easterlings. This attains great power through the ring and becomes a powerful magician until it corrupting the power of the ring and to one of Nazgûl power.
Here it shows Sauron’s true strength, which is in no way based on physical strength or magical abilities. Its true strength is to sow discord and pit people against each other. Over and over again.
Isildur, Boromir, Theodin and whole peoples succumb to his manipulation and his promise of power. But this power is only borrowed, because in the end he remains the mastermind, ruler and Lord of the Rings.
Incidentally, the clashes between the Easterlings and the free peoples in the West only arose when it aragorn managed, after the Wars of the Ring to reconcile the two peoples.