With all the force of the celebration it may be hard for the military to hold on. The US can't be seen now to countenance terror, and the protests from the beginning have been organized, and the activists politically mature. It's a bourgeois revolution and they're hard to destroy. And if there's no chaos there's no need for the army to impose order. Their claims to authority will be treated as insults. A functioning dictatorship requires a large segment of a population to agree to be treated as children. I don't know if that exists in Egypt now.