If you were to read The Hobbit (specifically the chapter called "The Battle of the Five Armies") and you know a lot about World War 1, you can see slight similarities between certain groups. The Goblins and Worgs have some similarities to the German and Austrian armies. The way they started a fight before needed and such. America could correlate to the eagles because they charge into battle after it had started and troubles had come down upon the armies fighting for good. The French, Russian, and the United Kingdoms could be represented as the Elves, Lakemen, and Dwarves. Such similarities can easily be looked over, but they do exsist.