Thanks. That saved me allot of time.

Hi I am new and I couldn't find a thread that answers this question so...
I have gone to the Ilwrath homeworld and I have been beating the snot out of them prettly easily so I though I could go ahead and invade their home. Well I do and I go into battle after battle going on to about 15 fights and I finaly die so I am wondering is it possible to invade a planet and win if not why is there fights if there is no chance to win.