The Muslim Brothrehood had waited for 80 years, suffering mightily at the hands of the various "rulers" from Nasser to Mubarak, but now having won power democratically, they have been displaced, with leaders under arrest. This will not sit well with their followers, who make up about 30% of the Egyptian population. The more militant will be joined by Jihadists from the region and will resort to violence.
The military, the only organised group (other than the Brotherhood), acted only after they were called upon by the "people", which give some legitimacy to its action, claiming to act only after talks with Morsi had failed ( they offered to let him stay on as president but with little power, to be a "front" for the military) but he refused, and so he was deposed and placed under arrest.)
The military has no friends, only its interests, which they are keen to protect. Their place in Egyptian society, as a class separate and distinct from the rest of society, as well as being the protector of the nation's sovreignity ( goes all the way back to Nasser and the overthrow of King Farouk, continued by Sadat and Mubarak), combined with their many busines investments, are what concerns them. "Social stability", is what they call it. They will act to protect themselves against all-comers. They do not want direct power.......they were severely "burned" 2 years ago when they took power after Mubarak (one of them). They want to control power, (and that is what Morsi refused).
Now here we are. The only organised groups in the society ( the Military and the Brotherhood. They dislike each other; their interests clash and their history is one of bitterness ) are ranged against each other with the rest of the "people"( anout 30% are liberals, secularists, leftists etc) in the middle. The other 40% or so are on the sidelines for the time being watching and waiting to see which way "the wind blows".
The USA, gives about $1.5 billion in military and economic aid to Egypt. They have had a close relation with the military and may try to use their influence , calling for elections and a return to democracy. There is also a $4.8 billion bail-out being negotiated with the IMF, that may come into play. The military will be aware of the implications, but it is the Muslim Brotherhood that will decide where this ends up.