hrm.. not sure about this one... the following fic doesn't meet all the criteria you stated, but it has Naraku and Sesshoumaru going to war against Inuyasha and Inu no Taisho...
Revolution by Pensierri32
She had taken from him everything he had built, cherished; and for that, she would help him rectify the mistaken, twisted desires of the Jewel of Four Souls. She would help his people survive, assist their revolution. She would become his in every way. SK
Inuyasha - Rated: T - English - Adventure/Romance - Chapters: 6 - Words: 25,712 - Reviews: 28 - Updated: 11-14-11 - Published: 10-17-11 - Sesshomaru & Kagome
Also, I think there used to be more chapters for this story, but I believe the author is doing a rewrite.