Fortified checkpoints manned by bored Lebanese soldiers surround the south Beirut suburbs known as the Dahiyeh, a stronghold of the Shia Hizbullah movement.
The area has been repeatedly targeted by Sunni jihadis in retaliation for Hizbullah’s military involvement with the Syrian army battling insurgents seeking to oust President Bashar al-Assad. Traffic is obliged to slow, pause and slalom through concrete blocks positioned to prevent attackers in speeding vehicles entering this vulnerable region, struck by eight major bombings over the past 15 months.
At rush hour, vehicles can be stalled for long periods entering or leaving the Dahiyeh, particularly if troops on red alert are ordered to search them or inspect identity cards.
Checkpoints also abound on the approaches to the picturesque north Lebanon mountain resort of Hermel, located in another Hizbullah-dominated region near the border with Syria.
Hermel has suffered three attacks, while one has taken place in the Sunni-majority port of Tripoli and two in the aggressively Sunni border town of Arsal, which hosts fighters from Islamic State (IS) and the al-Qaeda-affiliated Jabhat al-Nusra. These two groups fight each other in Syria but cooperate in the Lebanese-Syrian borderlands.
The Lebanese army has drawn a tight cordon around Arsal, with the aim of preventing fighters from pouring into Lebanon and anti-jihadi locals from burning refugee tents.
Arsal, with 35,000 residents, has received 110,000 Syrian refugees, most of whom dwell in tented camps on the outskirts. Refugees have raised the black IS flag to protest against an army operation involving the arrest of militants suspected of collaborating with jihadis in a clash with troops on August 2nd.
Hizbullah is concerned about jihadi infiltration from Deraa, in southern Syria, into its hinterland of south Lebanon. From there the jihadis could lob missiles into Israel, risking Israeli retaliation against Hizbullah.
Jihadi attacks against Hizbullah, the Lebanese army, political figures and public facilities could escalate in response to air strikes by the US-led coalition against IS fighters, headquarters and oil installations across the border in Syria.
IS and Jabhat operatives are said to be in Syrian and Palestinian refugee communities around the country and to have taken up residence in Christian and Druze urban neighbourhoods, towns and villages. Marie Nassif-Debs, who hails from the Greek Orthodox Koura region, said well-armed jihadis prefer “hiding” in such areas, rather than in Sunni locations where the security services have a strong presence and are on the lookout for “sleeper cells.”
Christian towns in the Bekaa Valley, Mount Lebanon and the Chouf have formed volunteer “watch” groups, while the Maronite Christian Kataeb Party and mainly Greek Orthodox Syrian Social Nationalist Party (SSNP) conduct patrols to avert bombings and kidnappings for ransom, a practice revived from the 1975-90 civil war.
Bekaa-based Shia and Sunni clansmen, whose traditional trades are smuggling and hashish farming, have also returned to kidnapping to boost funds. These clans are dominated by mafia dons who owe allegiance neither to the state nor to Hizbullah or Amal, which command Shia loyalties in Beirut and the south.
Abductions to secure swaps for clansmen taken by rivals are common in the lawless Bekaa. Last year the government, which from time to time cracks down on hashish farmers, kept its distance in order to foster good relations with the clans.
There is serious concern that the northern port of Tripoli could become a bastion of IS and Jabhat fighters who have migrated from Arsal and other Sunni border villages in the north.
daily newspaper reported that radicals have been indoctrinating and arming local men. Over the past few years there have been repeated bouts of bloodletting between the Sunni Jabal Mohsen quarter, which supports Syrian insurgents, and the Alawite Bab al-Tabbaneh neighbourhood, which backs the Alawite Bashar al-Assad.
As soon as the Syrian conflict erupted in 2011, it spilled over into fragile and fragmented Lebanon, now the third front in the war against IS. The Sunni mainstream Future party, led by Saad Hariri, adopted the insurgents, providing them with arms, funds and recruits. Hizbullah supported the Bashar al-Assad's government politically and, eventually, militarily.
However, the emergence of IS as the most powerful militia in Syria and now Iraq has created a conflict in most Lebanese Sunnis who do not espouse its brutal behaviour. Nevertheless, the Future party, which dominates the main Sunni-Christian bloc in government, has been reluctant to act against Sunni extremists.
The government, headed by independent Sunni prime minister Tammam Salam – chosen because he commands only a small following – has refused to be drawn into the US-led anti-IS coalition while urging external powers to provide weapons for the Lebanese army to defend the country from enemies within.
Since gaining independence from France in 1943, Lebanon has suffered two civil wars, two Israeli military campaigns and an attempted coup. The divided country is now facing one of its greatest challenges as it tries to hold together against exploitation by external powers and factions.
"The country has survived horrific violence before, " said former finance minister Georges Corm. "I think Lebanon will be resilient and deal with [IS] if the army has more arms and the Sunni political establishment agrees."