Conspiracy

It was only after Fugaku Uchiha promised that the core management of the Security Force would remain in the hands of Uchiha clansmen, and that the Security Force would still retain a fairly large portion of its posts, that he was able to push the reform through successfully. However, the reason this reform succeeded was that Fugaku Uchiha possessed the overwhelming power of the Mangekyō Sharingan, enough to suppress every dissenting voice within the clan.