First, genuine revolutionary change – good or bad -- in regimes typically starts with the potentate-figurehead being told to go by his own army or security subordinates who realize their troops are unwilling or unable to stop the raging popular crowds and strikers. The Shah wasn’t pushed out by Khomeini or America but by his own security establishment. The Tsar of all the Russias in 1917 went the same away, with his army dropping the bad news, and leaving a legal vacuum. And it appears the CDR insiders told Ben Ali the same in Tunisia as popular crowds there aimed themselves as his palace.

I’ll trust Wikipedia for conciseness on one historical case:

. . .the ability of the garrison to hold back the protests was all but nullified, symbols of the Tsarist [regime] were rapidly torn down around the city, and governmental authority in the capital collapsed – not helped by the fact that Nicholas had prorogued the Duma that morning, leaving it with no legal authority to act. The response of the Duma . . . was to establish a Temporary Committee to restore law and order. . . .. When the Tsar finally reached his destination [by train] , the Army Chiefs and his remaining ministers (those who had not fled under pretense of a power-cut) suggested in unison that he abdicate the throne. He did so on March 15 [O.S. March 2], on behalf of himself, and then, having taken advice, on behalf of his son . . . .Nicholas nominated his brother, the Grand Duke Michael Alexandrovich, to succeed him. But the Grand Duke realised that he would have little support as ruler, so he declined the crown on March 16 stating that he would take it only if that was the consensus of democratic action.

Many differences but the theme and formula is the same or similar. The first step to wholy transformative (not always good) regime redirection is usually the security establishment letting it be known that they aren’t willing or able to protect The Leader, while an existing legal body declares extraordinary emergency measures.

If one sees the final desirable goal in Egypt as a civilian democracy, then while nothing definitely structural as yet has happened in removing Mubarak, neither is the actual coup overly ominous. In fact, the "revolution" aspect that matters most in Mubarak’s departure has already occurred, perhaps even before he left. More on that further down, but first the basics of why a coup ain’t such a bad thng.

First, a military coup in a military regime is a net zero institutionally speaking, neither good nor bad in itself. Second, a supreme military action that suspends the operation of a constitution that actually constitutes the military regime’s own self-written cookbook for behind-the-scenes power maintenance is not all bad. Actually it's quite a promising implicit rejection of the former ways of doing politics. That is because it creates a sufficient legal vacuum to allow an actual transition of regimes ahead.

Relying on the old instruction manual which has safeguards for Phaoronic power-preservation including emergency laws, limited succession powers, and rigid election timetables may actually muck up a healthy transition and future democratic election. So the extra-constitutional action by the Military Grand Poobah Roundtable might be one of the most promising developments.

Most important however by far is the psychological revolution. That was initiated in Tunisia first, and then validated in real time drama in Egypt. The psychological revolution is the elimination of the mystique of superhuman Big Brother-like authority. The core problem is not that Middle Eastern/North African leaders -- and for that matter most other non-democratic leaders -- to date don’t escape except by involuntary natural or assisted death or exile.

The problem is fundamentally that the Arab peoples to date have never broken the fear of telling The Man in the Ubiquitous Giant Photo to f**k off, and to do so to his giant feared and despised face publicly and en masse. And to do so without a new Big Leader face driving it on, like Iran’s Khomeini, appearing as a new candidate to replace the old Oversized Poster Boss.

Well, until Tunisia, that is. And now Egypt.

That is the fundamental revolutionary shift and revolution that took place. It isn’t everything; it isn’t the final goal. But it required the success – by coup or mob or lightinng or poison, it doesn’t matter too much -- of seeing the homegrown Demi-God being defeated by a spontaneous and courageous exercise of popular will along with the stamina to see it through. Unlike anything seen before in at least the Arab countries, at least modernly in living memory.

That shedding of fatalism and the seizing of a sense of citizenship with right and duty to change one’s own indigenous government and to go on and actually be able to do that is the revolution. Whether the success comes by the secondary cause and effect of a coup or a well-placed transparent banana-peel “accident”, the fact that it came quite clearly in response to an undeniable assertion of popular will and mass citizen participation in public life is what makes this first step so critical and the precise manner of it less so.

And the people “got” this. They understood it may be a coup at first. Their slogans, such as the “people and the army are one” were practically an invitation to the army to get up and go a-couping.

Related to all that is seeing the success of a subversion of the two systemic forces oppressing and holding back and down people in the region. And no, one of them is not religion, though it can be an enabler. No, one is the extended-family control of public and private life, which is really the cross-generational control of the youth by the elderly. The other is the class system.

In this revolt, both were subverted with a successful conclusion. The sharing of resistance and demonstration duties side by side in Cairo and other places among educated and fellahin, street urchins and doctors, unions and businessmen, was, again, revolutionary. And the removal, Tunisia-style, of the leader due to popularly organized anger, whether the immediate means were by coup or resignation or mob-burning or whatever – it doesn’t matter. All ways constituted the validation of the subversion of the class system.

More important in some ways was the “youth” factor. Older folks followed the young people, as proud examples and redemptions for themselves. Ghonim, the youngish Google guy, not only inspired older folks but clearly made decisions. One thing notable about Mubarak’s speeches was his old-fashioned appeal to age – condescendingly patting the youth on the back and referring to himself as a wise father admonishing his kids. That such rhetoric didn’t fly and backfired says a real lot iabout the end of the age-hierarchy in socio-political direction.

Ultimately, it all could fail, and regime change, in the sense of dissolving the 60 year Free Officer regime and replacing it with real civilian democracy is a rough uncertain road ahead. Most or many similar revolutions crash on some diseased factional rock. But even if change does work, historically hammering out the end-game is rarely a 10 day to two week thing, as opposed to the usual sudden initial conflagration causing the collapse of the Leader.

The Russian revolution involved a year of subversion and countersubversion and then a few years of civil war. Khomeini consolidated over a few years actually. The French Revolution took two years just to behead the king. Apartheid didn’t roll over in a day. Pinochet was voted down in 1988 but didn’t step down until 1990. Good or bad, revolutions take time to reach their conclusion.

Often, however, it starts with a military hierarchy giving in to the change and instructing the Big Boss to pack up. A journey of a thousand institutional coups begins with a single coup.

The longer-term virtue here though remains the psychological break with the mystique of authoritarianism, and with a positive embrace of aggressive citizenship with successful rsults. I think it is safe to say that happened in Egypt. A coup was the first decisive step reinforcing the practical effect of the popular change in approach to their governments. Additionally, with a constitution-dodging maneuver taking place in that coup, it may also serve give easier legal effect to future salutary institutional metamorphoses.