Anti-Dwarves

[Rumil]

If I remember, the reference to Sauron-supporting Dwarves comes at the end of the Second Age, with the Last Alliance. It was said that all peoples save the elves were split, with some supporting Sauron, others the Alliance. Of Dwarves, few fought on either side (implying at least some DID fight for Sauron) but the House of Durin fought on the side of the Alliance.

I'd guess that although Sauron the arch-manipulator could not use the seven rings to reduce the dwarves to obediance he could surely have exploited their enhanced greed and pride to set one against the other and so capitalise on their disunity.

By the time of the War of the Dwarves and Orcs in the Third Age, all Dwarven Houses were said to have sent reinforcements, so the disunity would seem likely to have been cured, perhaps at the point of an axe!

The other unfortunate incident was the whole Nauglamir thing, where the Dwarves of the First Age destroyed Doriath in another jewelry-related tiff. Even Gandalf appears non-committal on whose fault this one was though.

[Kuruharan]

It's painfully obvious that greedy git Thingol was trying to stiff the noble craftsdwarves of their justly earned fee...

EDIT: This relates to the idea that the natural adversaries of dwarves were other dwarves.

A warlike race of old were all the Naugrim, and they would fight fiercely against whomsoever aggrieved them: servants of Melkor, or Eldar, or Avari, or wild beasts, or not seldom their own kin, Dwarves of other mansions and lordships.