Lebanese are used to foreign meddling in their politics. Some might say, Lebanese politics are defined by it. But not since the 2006 war with Israel and the 2005 assassination of former prime minister Rafiq Hariri have more powerful neighbours threatened the country's stability so much.
Syria's troubles were always going to spill over into Lebanon given the complex overlap of kinship and communal ties. Is is perhaps surprising that the country stayed relatively peaceful for so long as Syria spiralled out of the Assads' control.
That is a cold comfort as the past week in Lebanon has seen the worst violence yet. At least 13 have been killed, and more than 70 injured, in recent fighting in Tripoli. Local politicians' attempts to negotiate a ceasefire between Alawite and Sunni neighbourhoods in the northern city were marred yesterday as sniper fire continued to terrorise the streets.
The Lebanese army has deployed across Tripoli to enforce the ceasefire, but its ability to force the combatants to stand down is in doubt.
Part of Lebanon's fragility comes from the indisputable fact that the state is not the only - or indeed the strongest - military power in the country. Hizbollah keeps a leash on its powerful militia, and will probably continue to do so, but it is a reminder of why Lebanese politicians need to do everything they can to prevent the violence from spreading.
There is credible evidence that Syria's regime is deliberately trying to pull its smaller neighbour in. Former MP Michel Samaha was arrested earlier this month on charges of planning a string of bombing attacks, in coordination with Syria's security bureau. The Shia Meqdad clan still holds Syrian and Turkish hostages in Beirut, demanding a family member's release in Syria.
The government has an unenviable task here, facing serious national security challenges while negotiating its own factional loyalties. Prime Minister Najib Mikati's administration - notably undistinguished since it took office in June 2011 - has done well striking a neutral tone throughout the crisis, despite Mr Mikati's links to what was once a formidable pro-Syrian camp.
In the past two days, Mr Mikati has reassured Lebanon that he will remain in office at least until an emergency government is formed. The last thing the country needs is a political vacuum. So far, most parties have adopted a cautious approach. It is in everybody's interest for the politicians to keep talking to prevent the violence on the streets from spreading.