Lebanon risks being plunged into sectarian strife, possibly even civil war, by the strains inflicted on its own delicate internal situation by the Syrian crisis
The main Lebanese Alawite faction, the Arab Democratic Party led by Rifaat Eid, is strongly linked to Damascus and is widely believed to receive arms and even instructions from the regime.
Most parts of Tripoli are clearly badged with the symbols of the struggle.
In many areas, the black-white-and-green banner of the Syrian revolution flutters, in places more prominently than Lebanon's own flag.
But in Jebel Mohsen, the posters are of Mr Assad and his father, the regime founder Hafez al-Assad, some of them featuring Rifaat Eid.
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The Alawites may be a small minority, but they are connected to a Syrian-backed alliance which includes the Shia factions Hezbollah and Amal, as well as some Christian groups - among them the northern warlord Suleiman Franjieh in nearby Zgharta.
"All the elements of a civil war are present," said Samer Annous, a university lecturer and civil society activist.
"Poverty, rage among many people over things that are happening in Syria, sectarian divisions, corruption in government, the total collapse of the whole system.
"It's just a pity to see our city again having to pay for the wars of others, regional powers including the Gulf states and the Syrians," Mr Anbnous said.
"It seems that there is a kind of competition between Qatar and Saudi Arabia to control the Sunni street in Lebanon, and especially in Tripoli,"
Qatar is the lead country in the Gulf supporting the Syrian rebels. It seems that it is using Tripoli and north Lebanon to get access to Syria. There are a lot of expensive new weapons on the front line here, and they're not left over from the civil war
Hezbollah's reaction to a Syrian collapse would set the frame for what happens next in Lebanon.