In Moria, in Khazad-dum.

[Belin]

But we will not enter Khazad-dum. You will not enter Khazad-dum.Only I have looked through the shadow of the Gate. Beyond the shadow it waits for you still: Durin's Bane. The world must change and some other power than ours must come before Durin's Folk walk again in Moria.

After the Orcs invaded Moria, its Dwarves were cast into some kind of exile, broken only by Thror, who was not at his most sane at the time. As the quote above shows, driving the orcs out was not enough to reclaim the place, which seems to have been tainted. What is the nature of this exile, and what was special about the dwarves that broke it?

I think that the "other power" refers to the awakening of the Ring, which would mean that Balin's attempt did not violate this prediction. However, Balin didn't know this, and neither did his followers. So... what was he thinking? Why was he willing to enter Moria, and how did he get anyone to come with him? What had changed? He strikes me as far more stable than Thror or even Thrain.

Then again, Gimli, without having any knowledge of what had happened to Balin, or whether he'd succeeded or not, was (although not without apparent necessity, it is true) eager to enter Moria as well, although unlike either of the others, he was on a completely different errand. What, I wonder, was going through his mind?

--Belin Ibaimendi