Just expanding what Keyrock said above: in the book Unfinished Tales, Saruman, Gandalf the other wizards were ordered to go to Middle Earth and help/guide the people in their conflict with Sauron. Iirc, they were expressly forbidden to solve the problem on their own, because the people of Middle Earth had to fight for what was theirs or something like that. I guess that includes calling the Eagles.
For me the funniest thing though is that all the problems Sauron caused after his boss (Melkor) was defeated could have been easily prevented. Again, I don't know if I remember this well, but in the Silmarillion when they capture Melkor they order Suaron to cross the ocean to face judgement. Sauron initially regreted his crimes, for real, but then he realized that if he went there he would be severely punished and then he decided to stay. And this was stupid, because the guy who arrested Melkor (with the help of an army) didn't consider himself with the authority to arrest Sauron, although Sauron was of a lesser status than Melkor.