Between 11-15 May, the US and Iran exchanged proposals for peace. Iran’s proposal was rejected by the White House as a “demand for surrender”; US President Trump called the proposal “unacceptable." Among other reasons, the inclusion/exclusion of Lebanon (read Hezbollah) has emerged as a major sticking point between the two. Previously, during negotiations in March and April 2026, Iran maintained a strict, non-negotiable stance that Lebanon and Hezbollah must be explicitly included in any regional ceasefire agreement. Iran has consistently threatened to withdraw from the two-week truce if Israel continues its attacks on Lebanon.
Both Israel and the US have rejected Tehran’s demand. President Trump has asserted that the Israel-Hezbollah conflict is a “separate skirmish.” Finally, under Iranian pressure, on 17 April, a ten-day ceasefire was announced between Israel and Lebanon. Iran’s Foreign Ministry welcomed the development and framed it as a “Victory for the Axis of Resistance.” Israel has, however, continued attacks on Lebanon, particularly in South Beirut and southern Lebanon, both long considered Hezbollah strongholds.
The following are the four reasons why Tehran insists on including Hezbollah and a regional ceasefire.
1. Hezbollah is Iran’s most trusted, loyal, and capable ally
Since its formation in 1982, with Tehran’s assistance, Hezbollah has remained Iran’s most trusted, loyal, and capable regional ally. While deeply aligned ideologically, Hezbollah has also publicly acknowledged its allegiance to the Iranian Supreme Leader. Over the years, its members have been trained and armed with the help of the Islamic Revolutionary Guard Corps (IRGC) and its Quds force. Hezbollah is also touted to have trained and armed other Iran-aligned groups in the region, particularly Hamas and the Houthis.
Hezbollah has proven its loyalty time and again, first by joining the Syrian Civil War on the side of Bashar al-Assad, a long-term Iranian ally, and recently by retaliating against Israel for the assassination of Iran’s Supreme Leader, having withheld attacks despite Israeli violations of the 2024 ceasefire.
Hezbollah is also the most capable of all Iran-aligned groups in the region: Before the 2023 conflict with Israel, it boasted several thousand troops, modern weaponry (drones and missiles allegedly provided by Iran, including the transfer of technology for domestic production); and the capacity to target Israel on its northern border. In essence, it was the linchpin of Iran’s “Axis of Resistance” in the region, and if rearmed and reorganized by Iran (as reports suggest), it will continue to be the cornerstone of Iranian security architecture in the region.
2. Iran cannot afford to be viewed as abandoning its long-term ally
The 2026 war has raised serious question marks over Iran’s credible deterrence, especially its forward defense strategy, wherein it cultivated mostly Shiite armed non-state groups across the region to project its power regionally against adversaries like the US, Israel, and Saudi Arabia and keep a direct conflict from reaching its borders. While this strategy did not deter the 2025 and 2026 US-Israeli attacks against Iran, these groups helped open multiple fronts that created unique pressure points. For instance, Hezbollah, with its capacity to directly target Tel Aviv, entered the war on Iran’s behalf and forced Israel to deal with another front on its northern border. The Houthis threatened to resume attacks in the Red Sea. With Hezbollah weakened and Hamas decimated, Iran cannot afford to alienate other partners in Iraq and Yemen. Moreover, several reports have indicated that Iran wants to buy time for Hezbollah to recuperate and is thus inflexible on Hezbollah’s inclusion.
3. The Shia factor
Iran has for long projected itself as the leader of the Shia world and harbours ambition to be the leader of the Muslim Ummah. These ambitions have been complicated by the fact that most of Iran’s neighbouring countries are majority Sunni countries, albeit with significant Shia populations. Over the years, Iran has used this demographic reality to curry support of the minority Shia populations across the region. Most of Iran’s proxies/partners/allies in the region are Shi’ite armed groups (excluding Hamas). Hezbollah in Lebanon is a case in point. Additionally, there are deep political and socio-cultural links between Iranian and Lebanese Shi’as. It is thus unsurprising that the ending of hostilities in Lebanon is a red line for Iran for it cannot legitimately claim to be the leader of the Shi’a world and abandon its historical promises.
4. Israel’s recent advances (and successes?) against Iran’s regional allies
Iran and Israel have fought a decades-long shadow war, with both viewing each other as an existential threat. Israel’s recent offensive in Gaza and Lebanon has not only weakened Iran’s allies but also created an opportunity for Israel to expand into these territories on the pretext of creating a buffer zone. This has, however, essentially translated into Israel expanding its borders into both Gaza and Lebanon. For Iran, any expansion of Israeli territory would be unacceptable. A ceasefire including Lebanon would naturally fix this conundrum for Iran.
To conclude:
The inclusion of Lebanon in the ceasefire will continue to be a red line for Tehran unless the separate negotiations held this week between Israel and Lebanon deliver something concrete, especially to Tehran’s liking.
