According to some, Malachim, DO have bechira. They just have such clarity of understanding that it wouldn’t occur to them to rebel.
Maaseh Satan is obviously referring to what Hashem has allowed the Satan to do to test Klal Yisrael. That test of Zionism has been a smashing success (or failure, depending on your perspective), unfortunately.
Of course, the Satan has no independent powers outside of what Hashem grants him, as with everything else.
To help illustrate this, the Egel HaZahav was clearly allowed by Hashem to happen, but it was obviously not what He “wanted”. Neither, obviously, did He “want” the State of Israel, as is amply clear now to any objective observer of history.