Last week, US ambassador to Lebanon Lisa Johnson handed a ceasefire proposal to the country’s Parliament Speaker, Nabih Berri, to bring the fighting in the country to an end. Mr Berri is the main Lebanese interlocutor with Hezbollah. A day later, an Iranian special envoy, Ali Larijani, arrived in Beirut to discuss the Lebanese response to the draft ceasefire proposal. This sequence of events revealed a great deal.

Since Hezbollah’s political and military leaderships were decapitated by Israel, Iran has come to play a direct role in the group’s decision-making. It may have been an anomaly to see Mr Berri reviewing a ceasefire proposal addressed to Lebanon with a foreign official, but the war in Lebanon is effectively now a conflict between Israel and Iran, with the Lebanese serving as Iranian cannon fodder.

Whatever else happens, Iran’s position in Lebanon is bound to come under increasing stress in the coming months. Most of the country’s communities would like to see Hezbollah disarmed and its weapons integrated into the state. This has left the group isolated at home as it continues to face a major Israeli onslaught, which is likely to escalate if no ceasefire agreement is soon agreed to.

Yet Iran has little incentive to accept the US proposal passed on to the Lebanese, largely because it sets up a committee, reportedly to be headed by an American general, to implement UN Security Council resolution 1701. The plan, which the US envoy Amos Hochstein discussed with Lebanon's parliamentary speaker on Tuesday in Beirut, calls for a Hezbollah withdrawal to the Litani River, but also reaffirms past UN resolutions requiring the disarmament of all militias in Lebanon, including Hezbollah.

The US ceasefire plan was concocted with the Israelis, and some have described it as a take-it-or-leave-it offer. Any Lebanese rejection of its conditions could allow Israel to widen its operations to grind down Hezbollah militarily. The Israelis have repeatedly indicated that this is their preference.

What are Iran’s options in light of this? It is widely believed in Lebanon that Iran appointed Naim Qassem as Hezbollah’s secretary general to succeed Hassan Nasrallah, and that its hold over him is near complete. There are even rumours the new secretary general was transferred to Tehran so that Israel could not assassinate him as they did Nasrallah and his anticipated successor Hashem Safieddine.

In a sign of the mood in Beirut, the Druze leader Walid Joumblatt lamented the fact in an interview last week that with Nasrallah dead, “there no longer is a local interlocutor” in Hezbollah. Instead, it was preferable in this case “to deal with the Islamic Republic”. This perception may come back to haunt officials in Tehran.

The Iranians do not want to lose their Lebanese card in the Axis of Resistance, and therefore are encouraging Hezbollah to fight on against the Israelis, in the hope that if the group is successful this would allow Iran to engage in talks over a ceasefire, through Hezbollah, from a more advantageous position. Beyond that, the Iranians must also be foreseeing eventual direct negotiations with the incoming US administration under president-elect Donald Trump, and, again, wouldn’t want to enter into them with their major regional ally militarily debilitated.

This suggests that, for now, both Hezbollah and Lebanon’s Shiite community will continue to pay a heavy price because of Iran’s calculations. This comes in a context where the tide may be turning against Hezbollah. With southern Lebanon cut off from the rest of the country and under constant surveillance from Israeli drones, the group will find it more and more difficult to resupply its forces there with rockets.

As the war drags on, the significant Israeli superiority on the ground may increase, with reportedly more than 50,000 troops stationed in the border area. Such a force is not there just to enter border villages and blow up Hezbollah tunnels; it is present for a much larger push, which the Israelis may be planning for when Hezbollah has been worn down further and its weapons supplies depleted.

If so, Iran’s decision to have Hezbollah soldier on rather than to reassess its entire Axis of Resistance strategy, may prove suicidal for its Lebanese allies. It might not only lead to more destruction of Shiite areas and Hezbollah’s decisive weakening, but also alienate a community already paying a prohibitive price for the conflict.

Israel may also conceivably expand operations in Syria to try to cut off Hezbollah’s arms supplies from Iran. Already, bombings have escalated in recent days, targeting the border area of Qusayr and individuals apparently involved in the supply network based in Damascus. Amid reports that the Israelis are building a road in the demilitarised zone in the Golan Heights, it is possible they are preparing an escalation to neutralise Hezbollah and Iranian forces on the Syrian-controlled side of Qunaitra.

Under these circumstances, and with the US supporting Israel, the Iranians may soon find that their options have narrowed dramatically. Allowing the conflict to persist in the hope that things might improve is a risky strategy, especially if matters end with Hezbollah crippled and much of southern Lebanon occupied.

Iran still has a base of support among Lebanon’s Shiite population, but it must accept that if it prioritises its militarised Axis of Resistance approach, which has been catastrophic, it may lose everything in the country. The Shiite community has been deeply dislocated, and for Tehran to allow this situation to worsen in order merely to save itself would be a cynical choice that could permanently undermine its regional sway.