Do you think that Egypt will try to attack Israel?
I strongly suspect that Morsi was gearing up for an eventual move in that direction, and the military is in the process of forestalling him. They may have, behind the scenes, been responsible for the demonstrations.
Morsi is at heart, an ideologue. The military leaders are more realistic, and certainly do NOT want to see 90% of Egypt's productivity, such as it is, damaged, if not destroyed outright.
What we see in the news (such as it is) is more than likely illusion, masking the *real* issues at stake, which if truly known would terrify most people in the implications...