An Altmer or Bosmer sleeper agent from the Thalmor. Same reasons as Mao telling his men to be nice to the towns he occupied.

Race has nothing to do with motivation, and nothing but motivations matter. As long as the character feels Skyrim is better off independent and is willing to fight for it to happen, race doesn't matter one bit.

Nords...and Nords. Perhaps Redguards. Maybe some Imperials.