Balrog vs 200 000 dwarves ?

[Sarumian]

Originally Posted by Draugohtar

I'm still curious as to why you think the Wise would abandon all their other duties ie guarding Lothlorien, Rivendell, the Havens, marshalling the people against Sauron: to go on a needless jaunt into the bowels of Moria to fight some ancient evil. It was contained where it was, why seek extra peril?

The reason may be that a Balrog can one day leave Moria. While Sauron was absent, the Balrog had a potency to become a new Dark Lord. With Sauron back, both perspectives of Sauron subduing the Balrog or the Balrog obtaining The Ring were equally perilous.

However the nature of Durin's Bane was not discovered until the Company arrived and as it had never left Moria, no-one actually wanted to investigate the matter up to that time. Only some dwarves but they had failed to publish their findings