Iran shifts to direct fire to shield Lebanon, endangering ceasefire talks

Iran launched its first direct attack on Israel in two months on Sunday evening, after weeks of warning that Israeli strikes on Lebanon would endanger diplomacy, casting fresh doubt on the prospects of a US-Iran peace deal.

As Israel and the US sought to separate the occupation of southern Lebanon from the broader US-Israel war against Iran, Tehran insisted it would not consider any peace agreement that did not include Lebanon. Sunday night's attack confirmed that stance.

Following an Israeli raid on Beirut's southern suburbs on Sunday—despite US assurances the previous week that Israel would not strike the Lebanese capital if Hezbollah halted attacks on northern Israel—Iran fired missiles at Israel in retaliation. The Islamic Revolutionary Guard Corps (IRGC) declared: "Tonight's operation is a warning; if the aggressions are repeated, the reactions will be broader and encompass all US-Zionist targets in the region."

Israel responded with multiple strikes on Iran on Monday, including Tehran, even though US President Donald Trump was reportedly urging Prime Minister Benjamin Netanyahu not to escalate. Trump told the UK's Financial Times on Sunday: "I decide… He [the Israeli PM] does not decide." Tehran then fired a second salvo of missiles at Israel. Most Iranian missiles were intercepted, and no casualties were reported in Israel.

Nevertheless, the US president was forced to post on social media late Monday to caution both sides. He wrote on Truth Social: "Israel and Iran must immediately stop ‘shooting at each other."

After the second wave of attacks, the Iranian military declared an end to operations targeting Israel but warned that any further Israeli strikes on Lebanon would be met with "harsher" retaliation, Iran's semi-official Fars news agency reported.

"Tehran endured recent Israeli attacks on southern Lebanon but drew a red line at Beirut," Negar Mortazavi, a senior fellow at the Center for International Policy and founder of The Iran Podcast, told Al Jazeera. "When Israel sought to strike Beirut last week, Tehran sent a serious warning to Washington that it would not tolerate attacks on Beirut, and has now proven that warning was no empty threat."

The escalation raises the question of whether Iran is prepared to enforce its red line that any Israeli attack on its allies will trigger direct Iranian strikes, and whether Washington has any chance of negotiating an end to the war with Iran while Israel continues its military operations against Hezbollah in Lebanon.

Lebanon was drawn into the US-Israeli war against Iran on March 2 after Tehran-linked Hezbollah launched attacks on northern Israel. Hezbollah said the attacks were in retaliation for Israel's killing of Iran's Supreme Leader, Ayatollah Ali Khamenei, on the first day of the war, as well as Israel's near-daily violations of the November 2024 ceasefire agreement in Lebanon. According to the latest figures from Lebanon's Health Ministry, at least 3,613 people have been killed and 11,072 wounded in Israeli attacks across Lebanon since hostilities resumed in March. More than one million people have been displaced as Israel occupies nearly one-fifth of the country.

Although a US-brokered ceasefire intended to stop fighting between Israel and Hezbollah began on April 17, Israeli attacks continued in the following weeks, including on the capital Beirut, where Israel said it was targeting a Hezbollah stronghold in the city's southern suburbs. Earlier this week, Lebanese and Israeli negotiators announced another conditional ceasefire after talks in Washington. However, Hezbollah leader Naim Qassem rejected that ceasefire, calling it a sham and declaring that attacks on northern Israel would continue as long as bombs fell on Lebanon.

Rob Geist Pinfold, a lecturer in international security at King's College London, said Iran is increasingly abandoning its long-standing regional strategic logic. "Initially, the whole point of 'forward defense' was to prevent direct conflict between Israel and Iran." Iran heavily invested in Hezbollah and other allied groups because it believed these groups could create proxy power and deter Israel more effectively than Iran's own conventional military capabilities. "What we are seeing here is Iran completely reversing that dynamic. Instead of using these proxy groups to fight for Iran, it is escalating as a state to fight for its proxies."

Mortazavi said Iran has now tied any peace framework to the fate of its regional allies. "Tehran's message is: Together in war, together in peace." Nadim Houry, executive director of the Arab Reform Initiative (ARI) in Lebanon, argued that Iran is trying to preserve its long-standing strategy of "unifying the fronts." "To do this, it needs to demonstrate that it can prevent Israel from acting unilaterally against Lebanon," Houry said. "Iran's fear is that if it appears unable to defend Hezbollah, then its proxy groups across the region will be weakened one by one."

Andreas Krieg, a professor at the Department of Security at King's College London, stated: "Iran has drawn a much harder 'red line' around Lebanon than previously." He explained that Iran is attempting to redraw the boundaries of a ceasefire through calibrated force, rather than abandoning diplomacy altogether. "This is a new 'red line,' but a flexible one. Iran wants ambiguity. It wants Israel to believe further escalation in Lebanon could trigger direct Iranian retaliation, but it also wants enough room to avoid being dragged into a full-scale war on Israel's timetable." Analyst Ali Rizk in Beirut believes Tehran may be calculating that Trump wants to avoid a larger conflict and achieve a negotiated outcome. "Trump, I think, would be willing to partially accommodate Iran's interests in Lebanon if that allows a deal addressing Trump's core issues, such as the nuclear file and the Strait of Hormuz."

Analysts caution that if Washington cannot prevent Israeli actions that Tehran deems unacceptable, Iran may conclude the US is unable to deliver the comprehensive ceasefire it seeks. "The key question is whether Trump is willing to meaningfully restrain Israel. Will Trump take concrete steps to pressure Israel, or simply go along?" Houry said. Rizk said Trump is in a "very difficult position" but is likely to pressure Israel to stop escalating in Lebanon. "Sacrificing talks with Iran just to allow Netanyahu to bomb Lebanon exposes him as more of an Israeli stooge than ever, which could be disadvantageous in the US midterm elections. Therefore, it is highly likely he will make a strong effort to prevent escalation from derailing diplomacy with Iran."

For now, experts believe a temporary ceasefire remains possible, but lasting peace appears far more elusive. "The more likely outcome is a pattern of sustained violence: talks continue, Iran and Israel continue to test each other, Hezbollah remains active, and the US tries to prevent the system from spiraling into a broader campaign," Krieg said.