Caroline Glick, deputy managing editor of the Jerusalem Post, comments to NRO from Jerusalem:

There has been a lot of Arab violence in Jerusalem this week mainly against police. The PA has been ginning up calls for a third intifadah since Mubarak was ousted.
This is part of a general Palestinian offensive we see with the missile attacks on the south, the massacre in Itamar, and the interdicted Iranian weapons ship. And it’s against the backdrop of Fatah’s renewed efforts to form a post-Mubarak unity government with the strengthened Hamas.
The Palestinians figure they can get away with this because of Obama’s antagonism towards Israel. They are convinced that the U.S. will oppose Israeli counterstrikes.