The most significant threat to the nascent US-Iran peace framework emerged on Tuesday, as Tehran’s top diplomat declared that the continued presence of Israeli troops in southern Lebanon would constitute a breach of the agreement. Foreign Minister Abbas Araghchi stated unequivocally that “without the withdrawal of Israeli forces from the territories they occupied during this war, the war has not fully come to an end.” The assertion, echoed by Iran’s lead negotiator in a call with Lebanon’s parliamentary speaker, places a condition at the heart of the deal that neither Washington nor Israel appears prepared to accept.

Viewed from Washington, the memorandum of understanding—brokered between the United States and Iran and not yet made public—is a bilateral de-escalation instrument that does not mandate an Israeli withdrawal. An anonymous American official briefed that the text contains no such requirement, a position that aligns with Prime Minister Benjamin Netanyahu’s insistence that the Israel Defense Forces will remain in southern Lebanon “as long as necessary.” The gap in interpretation is not merely semantic; it goes to the core of whether the deal can hold. Iran’s deputy foreign minister, Majid Takht-Ravanchi, separately told state media that the memorandum includes a clause on ending hostilities on all fronts, including Lebanon, and that a mechanism exists to address violations.

On the ground, the dissonance is measured in casualties. Lebanese authorities reported that Israeli drone strikes on vehicles near Nabatieh killed at least four people on Tuesday, even as the Israeli military said it intercepted rockets fired at its soldiers in the south. Iran’s armed forces command, Khatam al-Anbiya, claimed Israel had violated the ceasefire 84 times in two days and warned of a “harsh response” if the attacks continue. Hezbollah, the Iran-backed militia that triggered the Lebanese front by firing rockets in support of Tehran on 2 March, conveyed through its press office that it believes Iran will not sign a final nuclear deal unless Israel withdraws—a pledge Iranian officials have reportedly given the group.

Analysts in European capitals note that the contradictory signals reflect the fundamentally different strategic logics at play. For the Trump administration, the priority is a swift end to direct hostilities with Iran and a pathway to a nuclear agreement; the Lebanese theatre is secondary. For Tehran, the war is indivisible: its credibility with Hezbollah and its broader regional posture depend on securing a visible rollback of Israeli gains. Israel, which joined US strikes on Iran in late February and has since seized swathes of Lebanese territory, views any concession as a strategic loss.

The coming days will test whether the memorandum’s ambiguity was a deliberate diplomatic device to pause the fighting or a fault line destined to fracture it. If Iran proceeds to make Israeli withdrawal a precondition for signing the final nuclear deal, the tentative truce could collapse, dragging the region back into a multi-front war that the memorandum was designed to end.