BBC correspondent Jim Muir was in Lebanon in 1976 when the Syrian army moved in, and he has followed the Lebanese conflict through all its stages since then. Here, he looks at the historical and strategic implications of the Syrian withdrawal:
Rafik Hariri's killing became a catalyst for the Syrian withdrawal
Lebanon is undoubtedly moving into uncharted territory.
Although any long-running conflict tends to see history repeating itself, there are several new elements in the picture today which make the situation unprecedented and the future unpredictable.
One is the sudden upsurge of "people power" in Beirut in the wake of the assassination of former Prime Minister Rafik Hariri on 14 February.
The only vaguely similar phenomenon was in 1989, when thousands of people, not all of them Christians, rallied around the controversial Christian Prime Minister, General Michel Aoun, at the presidential palace in Baabda after he had declared war on Syria and vowed to "break the head of the Alawite regime in Damascus".
Barely 18 months later, after a sapping inter-Christian war between Mr Aoun and the main Christian militia, Syrian troops descended on Baabda and Mr Aoun fled to the French embassy and later to exile in France.
The Syrian move had a green light from Washington.
Damascus was backing the US-led coalition against Saddam Hussein in Kuwait at the time, so things were different.
It is worth recalling that Syria's military move into Lebanon in 1976 had the sanction of both the US and Israel.
The Americans acted as brokers clearing it with the Israelis.
The Syrian army's entry into Lebanon had US and Israeli backing
The Israeli Prime Minister at the time, Yitzhak Rabin, told me in a 1983 interview that he wanted the Syrians to come right down to the border, so Damascus could control it and be held accountable, but the Syrians stayed back.
The Syrian entry came at the behest of Lebanese Christian leaders and was essentially aimed at curbing the Palestinians, who were dangerously tilting the balance in the Lebanese civil conflict.
One of the top PLO leaders, Salah Khalaf, known also as Abu Iyyad, had famously declared that "the road to Jerusalem leads through Jounieh", the port town at the heart of the Christian enclave.
Again, things were different then.
Another of the basic elements that has changed is the leadership of the Syrian regime.
The late president, Hafez al-Assad, was a cool calculator with a long-term strategic view and a strong power-base in the Syrian military.
He ruled his country with a tight grip for three decades until his death in June 2000, ironically just 17 days after Israeli troops staged their final headlong withdrawal from South Lebanon, leaving the Syrians to rule the Lebanese roost.
As the Israelis found to their cost, Lebanon is as easy to step into as a quagmire and as difficult to leave.
Any outsider extended there becomes a target for his regional foes and their local allies.
Now it is Syria's turn. And a Syria under different management.
President Assad's son and successor Bashar has yet to demonstrate the qualities that brought his father to the top.
The signs are that the Baathist old guard has retained much of the power.
If indeed Syrian intelligence was behind Rafik Hariri's assassination, as is the general assumption in Lebanon and elsewhere, it was a momentous blunder for which the old guard would have been responsible.
It succeeded in galvanising the extraordinary and unpredictable coalescing of opposition forces inside Lebanon and a similar convergence of outside powers demanding a Syrian withdrawal.
The Saudis, who had sponsored the Taif peace agreement in 1989 and regarded Mr Hariri as their own, were outraged.
Even strategic ally Iran, committed to supporting Damascus against Israel and other foes, could not justify backing an unpopular and no longer justifiable occupation.
Protests in Beirut have been calling for weeks for a Syrian withdrawal
If Israel's overnight disappearance from South Lebanon in May 2000 could be seen - in its way - as a military rout, Syria's - also in its way - is a political one.
With the Americans forcefully demanding it, and demonstrating in neighbouring Iraq the potential consequences of defiance, to have lingered would have been to court disaster.
But as President Assad stressed in his speech announcing the pullback: "Syria's power and role in Lebanon do not hinge on the presence of the Syrian forces there... Syria's withdrawal from Lebanon does not nullify the Syrian role."
"This role is governed by many geographical and political factors and other factors. On the contrary, we will be more free and uninhibited in dealing with Lebanon."
Syria has a vital strategic interest in Lebanon, which guards its vulnerable western flank.
Damascus has spent the last three decades building up structures and alliances there, embodying a deeply-embedded influence of which its troop presence was only the visible and arguably dispensable tip.
"It's nonsense to believe the Syrians are pulling out with tail between legs - they still have very strong influence," said one long-term Lebanese observer.
Syria will aim to keep a close eye on Lebanon after its soldiers leave
"And the Lebanese are more grown-up now too. We have very strong economic links with Syria which are very important for Lebanon. We want good relations."
Bashar al-Assad served clear notice in his speech that Syria would mobilise all its assets in Lebanon if it found the country becoming a playground for its enemies, especially Israel.
In such a situation, Damascus could undoubtedly count on the active support of Hezbollah, the Iranian-created, Syrian-backed Shia militia which won the respect of most Lebanese - and grudgingly, many Israelis too - for its determination and sacrifice in driving Israel out.
Much will therefore depend on how the Lebanese opposition now plays its hand.
Israeli leaders have already said they would like to sign a peace agreement with Beirut once the Syrians are gone.
That would risk a repeat of the events which followed the signing of just such an accord on 17 May 1983, when the balance had tipped in Israel's favour.
Syria, Iran and their local allies teamed up to ensure that it never saw the light of day.
Veteran opposition leaders such as the Druze chief Walid Jumblatt are well aware of the risks, but the people's power alliance embraces others who might not be so prudent.
It also brings together political trends which were at daggers drawn through most of the past conflict.
Once the Syrians have gone, can they really shelve their differences, compromise, and assert the truly Lebanese sovereignty and independence to which they pay homage?
If that involves forging outside alliances again to try to counterbalance the Syrians, Damascus can be counted on to do its utmost to undermine any Beirut government which does not recognise the special nature of the relationship with Syria.
To succeed, the Lebanese factions will have to shake off a long history of internal rivalries and blood-letting, and a deeply-ingrained tendency to seek outside help against their local foes.
If they fail to do that, the country could easily once again find itself a battleground for local, regional and international struggles, as it was through the 1970s and 1980s.
But the current situation does open up the exciting possibility that Lebanon may soon hold truly free elections for the first time in decades, and produce a government which genuinely reflects the will and diversity of the Lebanese people and a shared determination to win real independence.