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human
[Lord of the Rings] Was there an army of dwarves assisting in the battle at the gates of Mordor? If not, why not?

I don't recall seeing many dwarves in the historical footage of the battle at the gates of Mordor. The only dwarf I remember seeing was Gimli. Were there other dwarves there? If not, where were they?
gpt
The Dwarves couldn't have helped even if they wanted to. 

Sauron's assault on Middle-earth was multi-pronged. Every major nation that stood against him - Dale, Erebor, Mirkwood, Lothlorien, Rohan and Gondor - were all attacked at the same time so that none of the nations could help each other. 

A large Easterling army assaulted Dale two days after the Battle of Pelennor Fields. That battle lasted for three days, and resulted in an initial victory for the Easterlings after the deaths of King Dain and King Brand and the retreat of their armies into Erebor. The battle only ended after news of Sauron's defeat spread north, and the Easterlings lost the will to fight and were beaten back by the Dwarves and Men of Dale after they sallied forth from Erebor.

Gandalf estimated that the Battle of Dale was just as important as the Battle of Pelennor Fields. If Erebor had been taken, Easterling forces could've then linked up with Sauron's armies from Dol Guldur, and then joined together in overunning Mirkwood and Lothlorien.

Edit - Sauron's strategy was incredibly thorough. He tied up all of his enemies at their homelands to stop them from helping each other, even attacking Gondor in multiple places to avoid Gondor's entire army from uniting. As a result, the only nation that managed to help another was Rohan (due to Saruman's failure), but even then, a force from Dol Guldur crossed into Rohan (but was destroyed by the Ents) and a force of Orcs and Easterlings fortified Anorien so Theoden's army could not reach Minas Tirith. The only reason why Theoden reached Minas Tirith when he did was because the Woses led them through secret paths in the Druedan Forest. 

Even Gondor could not field all of its forces in one place. When Pippin is in Minas Tirith, he watches the troops from Gondor's fiefdoms arrive to reinforce Minas Tirith, which number 3,000 in total. The onlookers are shocked, expecting several times that amount of soldiers to arrive. The reason they couldn't come was because Corsairs and Haradrim were planning on assaulting the Anduin and the coastline of Gondor. When Aragorn marches to the Black Gate, Minas Tirith is actually better defended than it was before the battle due to thousands of Gondorian soldiers arriving from the fiefdoms which are now safe from the Corsairs and Haradrim.