Speak with Kurun on the hill overlooking Thor Modan.
The old iron dwarf capital of Thor Modan, far to the northeast, is under siege by a mysterious band of stone giants and earthen.
Why the creations of the titans would war against each other is beyond my understanding and the Horde's interest, but there is an opportunity here to weaken a mutual enemy.
Travel to Thor Modan and seek out this 'Kurun' who commands the giants and earthen. Make common cause with him and use his forces to crush the iron dwarves.