Lebanon has remained resilient throughout the seven-year conflict in neighbouring Syria. However, the country once again finds itself caught in the winds of dangerous regional rivalries, not least that between Israel and Iran.

Iran’s Lebanese ally, Hezbollah, now has the strongest domestic military force in Lebanon, holding effective veto power over political developments there. The group’s active role in the conflict in Syria has been costly in lives and international standing, but beneficial in military experience and capability. Thus, Hezbollah has a fighting force that is more effective than ever before. Viewing Hezbollah as its front-line deterrent against the perceived Israeli threat, Tehran prioritises efforts to secure and expand the group’s access routes into Lebanon from Syria.

These efforts have considerably raised the stakes for an Israel that has perceived Hezbollah as unfinished business since 2006, when the sides engaged in an indecisive war in Lebanon. Israel believes that Hezbollah is pointing thousands of Iranian-supplied missiles its way, and that Iran intends to further strengthen the group through the provision of more powerful and accurate missiles and the establishment of a military presence in Syria, particularly in the Golan. This could allow Hezbollah to open a second front against Israel if it engages in another war in Lebanon.

But Israel is not the only regional state with increasing ambitions to diminish Iranian influence in Lebanon. In November 2017, Saudi Crown Prince Mohammed bin Salman seemed to orchestrate a failed bid to force the resignation of the Lebanese Prime Minister Saad Hariri. This was an apparent attempt to highlight Hezbollah’s ascendancy over the Lebanese state, by removing the perceived veneer of political legitimacy provided by the Hariri premiership and thereby provoking a crisis that could force Israel and the United States to harden their line. It may even have been an effort to provoke another war in Lebanon. Ultimately, the move turned Lebanon’s citizens against Riyadh and enabled Hezbollah to present itself as the most responsible actor in the country.

Saudi Arabia eventually backed down under strong international pressure. But the incident provided a reminder of how regional rivalries might unfold to worrying effect in Lebanon. It also highlighted Israeli unwillingness to be drawn into a war in Lebanon on Riyadh’s behalf.

Paradoxically, the pressure on Lebanon is likely to intensify now that the Syrian civil war appears to be approaching its military end game. Local and regional actors have long hedged their bets in Lebanon, waiting to see how the conflict in Syria would unfold. Now that the Assad regime and Iran are in the ascendant, domestic and regional actors are likely to recalibrate their positions in Lebanon. For now, Hezbollah and Israel appear to be engaged in a careful dance based on strong mutual deterrence. This allows them to avoid full confrontation with one another, even as they engage in periodic clashes.

Given the fragility of the Lebanese state, any escalation of hostilities in Lebanon – intended or otherwise – threatens to have a devastating impact. As Saudi Arabia has already made one apparent attempt to shake up Lebanese political structures and thereby weaken Hezbollah, it may take other opportunities to do so. In parallel, Israel and Saudi Arabia are pushing the United States and the European Union to extend their sanctions on Hezbollah across the Lebanese financial sector, in ways that could devastate Lebanon’s economy.

Any Israeli move to confront Hezbollah militarily in Lebanon could be devastating given that Israel has declared that it no longer distinguishes between Hezbollah and the Lebanese state – unlike in previous wars. Such a conflict could also quickly spiral into a wider war, given Hezbollah’s links with Syria.