One of the key inflection points in any revolution is the ultimate decision by the armed forces as to whether they will fire on the protesters. Generally, any decently-entrenched regime with a powerful military can survive street protests if the military continues to back it. If the military decides to stand down, however, things get a lot more interesting. This is one of the key differences between Egypt in 2011, and Iran in 2009. Iranian military and paramilitary forces were effectively deployed against the protesters, and demonstrated a willingness to crush the demonstrations. Moreover, Iran had a layer of redundancy built in — even if the army wavered, the army had to fear the Revolutionary Guard, which is fanatically loyal to the existing regime.
So what is it that made the Egyptian army different? Though not as tied into the state apparatus as the IRC is in Iran, it certainly was known as relatively loyal to President Mubarak. And here’s where things get interesting ….