When the Gaddafi regime finally falls apart in Tripoli – which it inevitably will – Libya's rebel's won't just have won a bloody and unlikely victory.

The Libyan rebels may very well have set in motion the first revolution of the Arab spring.

Tunisians started the fire and Egyptians scaled it up to the Arab world's biggest state, but in both cases, protesters stopped crucially short of breaking up entire regimes, settling instead for the downfall of the figurehead and a military-led transition to democracy. The people of both countries are now discovering the hard way that dismantling authoritarian systems is much harder when many of the authoritarian enforcers retain their power and weapons.

Protesters in Bahrain never really scratched the surface of the regime and have been crushed; in Yemen the system has proved elusive since its president retained his power but wields it from the sanctuary of neighboring Saudi Arabia.

But in Libya, the defeat of Gaddafi by the rebels will, by definition, mean a defeat of his security forces. The backing of NATO air strikes means the physical infrastructure of the regime, from intelligence offices to security headquarters and military equipment, has been severely downgraded to the point of collapse. The country will be the only in the Arab world where an opposition movement greets the new day with an old regime that is physically broken.

Syria is the only other nation where such an outcome seems possible, but even there, it is harder to picture the opposition overcoming an extremely loyal army. What looks more likely is a negotiated settlement, which will inevitably involve many of the regime's current functionaries and power networks – including economic lifelines – remaining in place.

The new leaders of Libya will also get an economic free hand. Control of key oil installations means they will control the nation's economic levers - not to mention the $70bn sovereign wealth fund that will be at their disposal. That gives the new government much more leeway on economic and social policy than the likes of Egypt, which faces pressing issues like a ballooning state deficit, rising subsidy costs and crushing poverty.

All of this means Libya has the potential to be the most exciting – or disastrous – Arab society to emerge from this year of uprising and revolt. Its new leaders face far fewer constraints in choosing the type of country Libya can become – unlike Egypt and Tunisia, there will be no military establishment to set limits on what is and isn't up for discussion.

If the change is radical, it would not be unprecedented. When Gaddafi emerged as a de-facto dictator after the country's 1969 revolution, he gradually outlined a vision of Libya as a jamahiriya (loosely translated as “people's republic”) ruled by a system of direct democracy, local people's committees and socialism. Soon, the country was, in theory, ruled by thousands of directly elected committees running everything from local schools to the national petroleum company, although in practice the system deteriorated into authoritarian one-party rule.

Regardless of its effectiveness, the system helped set many of the ideological fault lines that will inform Libya's revolutionaries as the seek to build a new governing system essentially from scratch. You work with what you've got.

Whether the dreaded, evasive felool (remnants) of the old regime will somehow retain their powers, as they have in Egypt and Tunisia, is yet to be seen. But whatever replaces the jamahiriya will be a truly new regime - a first in a year of firsts for the Middle East.

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Sunday in the Middle East is a weekly column. FT Tilt's MENA correspondent Tom Gara takes a birds-eye view of the Middle East as the region undergoes its most dramatic transformation in decades. See all our Sunday in the Middle East columns via this link - you can also subscribe by email.