Warning: This article contains spoilers for The Rings of Power season 2.
The Lord of the Rings: The Rings of Power has seemingly already provided the basis of Sauron’s war in season 2, tied to Mithril and the crafting of the remaining rings of power. The Rings of Power season 1 ended with the crafting of the three elvish rings, alongside the reveal that Halbrand was in fact Sauron in disguise. Another plot line of season 1 that was a retcon of Tolkien’s original works involved Mithril, the substance being mined beneath the Misty Mountains by the dwarves of Durin.
The main way in which the Mithril ties to the overall story, thus making Khazad-dûm vital to The Rings of Power, is by making the mineral intrinsic to the forging of the Rings of Power. At least in the case of the elven rings, Mithril was said to contain the light of a lost Silmaril, which in turn emboldened the elves’ power in Middle-earth. If this is extended into the rings of dwarves and men, then more Mithril will be needed to craft the rings. Also, as is known from The Lord of the Rings, Sauron intends to craft the One Ring, meaning he will need more Mithril. While it would fit Tolkien’s lore for Sauron to infiltrate Eregion through another form and manipulate Celebrimbor, the dwarves of Middle-earth could be in for a war with Sauron and Mordor, capitalizing on the showrunners’ promise of Sauron maneuvering out in the open.
The Rings of Power’s Sauron wants to craft the One Ring as the endgame for a plan hinted at in the show’s season 1 finale. In the scene in which Halbrand’s true nature is revealed to Galadriel, Sauron explains that he wants to unite the lands of Middle-earth under one banner and bring order to the world after Morgoth left it in chaos. Galadriel states that Sauron simply wants to rule the world rather than unite it, with the latter saying he does not see the difference. The One Ring, then, would allow Sauron to « unite » the world through domination, with the Ring being able to dominate all other Rings of Power (minus the elven rings).
If indeed The Rings of Power’s Mithril retcon of it being needed to craft the elven rings extends to the rings of men, dwarves, and the One Ring, then Sauron will need to obtain more to craft the latter and manipulate Celebrimbor into crafting the others. Through Sauron’s ability to change forms, he could easily manipulate Celebrimbor as Annatar like in Tolkien’s original works. However, obtaining the Mithril from the dwarves may be less straightforward. As the During and Elrond storyline of The Rings of Power season 1 ended with Durin being disowned by his father and the mines being closed off, it is hard to see how the Mithril will come back into play.
However, with the promise of The Rings of Power season 2 Sauron being more active with his plan, he could go to war with Khazad-dûm to obtain the Mithril needed. This could tie into the fall of Khazad-dûm, with the dwarves being hit by Sauron on one side and the Balrog on the other. This would be another great way to tie the Khazad-dûm storyline, which was fairly self-contained in season 1, into the overarching story of the show by making them directly involved in the war with Sauron. Regardless, it is clear that Sauron in The Rings of Power season 2 is going to be on the warpath, be it with Adar, father of the orcs in Mordor, Galadriel and the elves of Lindon, or the dwarves of Khazad-dûm.