The Islamic State (IS) terrorist group may be retreating in Iraq, failing in Kobani in Syria, and being disrupted by the continual air strikes carried out by the US-led international coalition. But it is still holding its ground in the rugged terrain of the Qalamoun Mountains that straddle the Lebanese-Syrian border. IS fighters are not only consolidating their positions, but may also be contemplating action that could further destabilise Lebanon. IS fighters are locked in battle with the rebel Free Syrian Army (FSA) and may be trying to get their hands on arms depots belonging to the latter. Reports suggest that the IS has been bringing in men and material from the Al-Raqqa governorate in Syria. As part of the route between Al-Raqqa and Qalamoun is controlled by the Syrian regime, this suggests that the regime may have knowingly allowed the reinforcements to go through. The local commander of the rebel Al-Nusra Front (NF) seems also to have forged a policy of cooperation with the IS, although the NF in general is fiercely opposed to it. During the onslaught on the Lebanese town of Arsal in August, the IS and NF were clearly acting in unison, dividing captured Lebanese army and police soldiers between them. Observers note that many IS fighters in Qalamoun are former NF combatants. Although the central organisations are at odds, the two local branches seem to be acting in unison. Amr Malek Al-Talli, the local NF leader, tends to act in coordination with the IS and has referred to IS combatants as “our brothers.” Once the FSA is out of the way, experts believe that NF fighters in Qalamoun may swear allegiance to the IS self-styled caliph Abu Bakr Al-Baghdadi. IS officials in Qalamoun have denounced the NF as “infidels,” but they have stopped short from denouncing NF fighters, leaving the door ajar for these to join their organisation at a later date. The IS seems to be the stronger of the two organisations, and with its continual supply of reinforcements, it may be able to convert NF fighters to its cause. Meanwhile, IS brutality, which the group is using as a weapon to frighten its opponents, is causing alarm in Lebanon. Although the IS has not made many inroads in Lebanon thus far, it makes no secret of the fact that it wishes to bring the country into its domain. The rugged nature of Qalamoun has so far discouraged the Lebanese army from taking on the Islamist militants. However, if the IS has its way in defeating the FSA and subsuming the NF, the threat it poses to Lebanon could become all the more real. The Lebanese army and security forces are on high alert, preparing for a possible IS offensive on the Beqaa Valley and trying to stop the terrorists from reaching the capital Beirut. Security officials still remember how Hezbollah positions in the Beqaa were targeted during the Muslim festivities of the Eid Al-Adha, and they are keen to prevent a similar thing happening during Christmas festivities in other parts of the country. In various towns of the Beqaa, Shiite, Christian, and Druze communities are massing arms and organising self-defence teams to ward off possible attacks. The Lebanese government has also asked France to speed up the delivery of the military planes it has ordered using a generous Saudi grant. The upside of all of this is that the heated debate over Hezbollah's weapons has been put to rest. No one is worried about the Shiite group anymore, and many – including its opponents – are thankful that Lebanon has a second line of defence against the IS militants. During a recent visit to Beqaa, Maronite Patriarch Bechara Boutros Al-Rahi praised the Lebanese army and the “resistance,” thus offering his blessings to the Shiite group that was once blamed for Lebanon's political deadlock. Key figures in the Sunni-dominated 8 March Alliance have called for the formation of self-defence teams in various parts of the country under the supervision of former army officers to keep the IS at bay. But the situation may prove trickier than it appears, for with 1.5 million impoverished and alienated Syrian refugees in Lebanon, IS recruiters may not have a hard time enlisting new members into the terrorist organisation. The refugees, initially welcomed with a measure of kindness, at least by fellow Lebanese Sunnis, are now in an awkward position. Many Lebanese, recalling the fact that Lebanon's civil war was triggered by a similar influx of Palestinian refugees, now view them with suspicion. Figures in the 8 March Alliance have noted that at least one-tenth of the Syrian refugees had served in the army in their country, and if even a fraction of them decide to join IS, out of need or conviction, the results could be catastrophic. But local officials in Arsal say there is no sympathy for the IS among the 120,000 Syrian refugees living there.