sauron and saurman

[Gurthang]

Yep, exactly. Sauron was playing Saruman like an old violin. Saruman needed to get close to the Dark Lord to have a better chance at finding the ring. Sauron saw through it, but also saw his chance to use this pawn(meaning Saruman) as an extra piece in the war. It would draw attention away from Mordor's attack, and create another front on Gondor if it succeeded. He had nothing to lose.