[JeffF.]

I think the Balrog could have done much to advance Sauron's military objectives. The three attacks by Dol Guldor & Moria orcs were repulsed but had the Balrog been there it may have been a different outcome. Even if Galadriel's power was too great unless Sauron himself came the Balrog leading Dol Guldor forces easily could have overcome the Beornings and Woodmen. Thranduil's elves also would have fallen. If the Balrog linked with the Easterlings attacking the Kingdom's of Dale and Erebor they would have overthrown all the North.