There are several versions of what happened in Arsal last Saturday. But whichever one applies, the Army must avoid being drawn into the Syrian conflict and taking one side against the other.

It will not be able to manage the consequences. For example, what Michel Aoun proposed on Tuesday is precisely what Lebanon should not do. Aoun declared, “I warn against carrying out negotiations with terrorists as we should negotiate with Damascus, not the Islamic State of Iraq and Greater Syria.” He added, “Monitoring the border is the responsibility of Lebanon and Syria, based on past agreements between the two countries.”

This was rank populism blended in with self-interest. No one has seriously suggested negotiating with the Islamic State in the first place. But for some time the Syrian regime and Hezbollah have sought to integrate the Lebanese Army into their own efforts to crush the rebels in the Qalamoun region, which stretches from Zabadani, near Damascus, all the way up to Qusair, near Homs. Aoun’s proposal effectively echoes that demand. What Syria and Hezbollah want is for the Army to cut the rebels’ resupply lines into Lebanon, so they can be defeated in Qalamoun.

The consequences would be exceptionally serious if the Army agreed to do so. It would mean taking part in Syria’s war, particularly on one of its most decisive fronts. One can expect the Syrian rebels, along with their Lebanese allies, to turn on the Army in order to undermine its efforts to close entry and exit routes into Qalamoun. This would only further destabilize Lebanon, turning the Army into a privileged target of the rebels. The repercussions could fatally harm sectarian relations.

That is not to say that the Army does not have a right, and a duty, to defend itself and ensure that the rebels, especially the extremists among them, will not exploit their access to Arsal in order to commit attacks in Lebanon. But becoming a partner in an offensive by the Assad regime and Hezbollah in Qalamoun is a far graver matter, marking the end of official Lebanese dissociation from the Syrian conflict. This is something that Prime Minister Tammam Salam must be very careful to avoid.

But will the Army commander Jean Kahwagi agree? Kahwagi has the presidency in mind, and his choices are not easy ones. If he refuses to implicate the Army in efforts along the border to suffocate the Syrian rebels, he risks alienating Hezbollah, which is his strongest backer to become president (despite the party’s claim to support Aoun). On the other hand if he does what Hezbollah and Syria want, he risks splitting the Army along sectarian lines, pushing Lebanon into a civil war, and almost certainly ensuring that Sunnis will reject his presidency.

Aoun is aware of Kahwagi’s dilemma, and seeks to drive the Army commander into the wall. That’s why he warned against talking to extremists. He wants to lock Kahwagi into a position that makes him less likely to adopt a median strategy in Arsal, one that balances the Army’s desire to avoid the risks of greater involvement in Syria with the rebels’ desire to keep border passages open. Aoun also wants to show Hezbollah and President Bashar Assad that, as president, he would do their bidding.

Walid Jumblatt met with Aoun on Wednesday, in an apparent effort to put an end to the presidential vacuum. Jumblatt feels that a new president would create a semblance of normality, helping to lower tensions in Lebanon. Perhaps, but after Aoun’s foolish position on border cooperation with Syria, it’s difficult to see him gaining any Sunni backing. If anything, Aoun’s election would exacerbate sectarian relations, with Sunnis viewing him as another facet of Hezbollah’s project to rule Lebanon

The Syrian gunmen in Arsal have done themselves no favors. Their attack against the Army and the abduction of soldiers and Internal Security Forces members prompted the military to react, opening the door to a more expansive interpretation of its role along the border, in line with Hezbollah’s and Syria’s desires. But the rebels appear to be divided, with reports on Wednesday suggesting that a large number had left Arsal overnight, even as other groups reportedly wanted to continue fighting the Army. Yet the gunmen would gain nothing by opening a front against the Army, nor by taking the inhabitants of Arsal hostage. The best they can do is withdraw to Arsal’s hinterland and avoid a clash with the Lebanese state. In return, this may prompt the Army to stand back and continue to contain the dynamics in Arsal, without moving decisively to cut the rebels’ supply lines.

That may not be ideal, but it would preserve the Army for its more urgent responsibility of preserving internal peace. Arsal’s hinterland is a difficult place to dominate and the Army would not be able to impose itself without being sucked into a debilitating foreign conflict that would only bleed it, without any obvious endgame. Hezbollah has been fighting in the same unforgiving terrain in Qalamoun, and has been unable to defeat the rebels.

Hezbollah also must know that if the Army were to break apart and Sunnis and Shiites were to go to war in Lebanon, the party’s entire Syria strategy would collapse. It would be forced to repatriate its combatants from Syria, leaving the exhausted and vulnerable Assad regime to face the rebels alone, while Hezbollah would be mired in an internal war it has no hope of winning.

That’s why the party must reconsider its efforts to persuade the Army to close the border near Arsal. This would bring only catastrophe to Lebanon, and likely to Hezbollah itself in the end. Kahwagi must have the courage to tell Syria and Hezbollah no, whatever it means for his presidential ambitions.