I'm looking for a book that was written by two authors about two warring nations of elves and hobbit-like people. The book cover has a small hobbit-like person in a shallow cave with a dragon looming over him. The title escapes me but I think the word dragon is in it. The conflict is based around a dragon destroying an air ship and both nations pointing the blame at each other. I know it's a vague description but would love if someone could help me out.