Toplines

Islamic Revolutionary Guards Corps (IRGC)-affiliated media has made Iranian implementation of the US-Iran agreement, particularly provisions concerning the Strait of Hormuz, contingent on an end to Israeli operations against Hezbollah in Lebanon. Iran is likely connecting these two clauses to compel the United States to pressure Israel to cease operations in Lebanon. Iranian and Hezbollah-affiliated actors have suggested that the memorandum of understanding (MoU) requires both a cessation of Israeli military operations in Lebanon and a complete Israeli withdrawal from Lebanese territory.[1] Iran reportedly pushed to add language guaranteeing the “sovereignty and territorial integrity of Lebanon” to the agreement’s opening clause, likely to strengthen its longstanding maximalist objective of securing an Israeli withdrawal from Lebanon.[2] IRGC-affiliated Tasnim News Agency explicitly linked implementation of the agreement to developments in Lebanon, arguing that Iran should keep the Strait of Hormuz closed as long as Israel continues operations there.[3] Tasnim further warned that Iran could suspend future negotiations, reimpose restrictions in the strait, halt the reopening process, or respond militarily to Israeli actions if the MoU is not fully implemented.[4] These articles follow claims by senior Iranian officials and bodies, including the Khatam ol Anbiya Central Headquarters and the IRGC, that Israeli operations in Lebanon violate the MoU.[5]

Hezbollah has twice initiated military operations against Israel since 2023 and entered wars without provocation. Hezbollah began attacking Israel on October 8, 2023, to support Hamas after it attacked Israel in the October 7 attack. Hezbollah again attacked Israel on March 1, 2026, to support Iran after US-Israeli operations began against Iran. Hezbollah seriously affects northern Israeli security, and its attacks have displaced Israeli citizens there. Israel is not a signatory to the MoU, even though the signatories added language that implied that Israel and Hezbollah were signatories. The MoU says that “the United States of America and the Islamic Republic of Iran and their allies in the current war are signing this MoU.”[6] Iran’s threats to collapse the agreement unless Israel ceases operations and withdraws from Lebanon likely reflect a deliberate effort to compel the United States to pressure Israel to end operations. Iran has surely observed reports in Western media that President Donald Trump prioritizes preserving the deal and has pressured Israeli Prime Minister Benjamin Netanyahu to limit military operations in Lebanon.[7]

The Israel Defense Forces (IDF) has continued operations against Hezbollah in southern Lebanon, despite Iranian insistence that Israel must halt its campaign in Lebanon as part of the MoU. The IDF stated on June 18 that it will remain deployed within the 10-kilometer-deep IDF “security zone” in southern Lebanon to remove Hezbollah threats to Israeli forces in southern Lebanon and Israeli residents in northern Israel.[8] Two Israeli officials told Reuters on June 18 that Israel recently held talks with the United States to discuss US approval for continued IDF presence in southern Lebanon.[9] Israeli media reported on June 18 that Israeli Prime Minister Benjamin Netanyahu told US President Donald Trump during a phone call that Israel will not leave southern Lebanon “as long as Israel’s security needs require it.”[10]  Trump stated in a social media post on June 18 that the United States expects a complete ceasefire on all fronts, including in Lebanon between Hezbollah and Israel.[11] Hezbollah, Iranian officials, and Iranian media have continued to claim that the US-Iran agreement requires Israel to cease operations against Hezbollah and ultimately withdraw from southern Lebanon.[12] Both sides have continued to engage one another in southern Lebanon, including beyond the Yellow Line.[13]

Iran, under the current MoU, retains the ability to use the Strait of Hormuz as a tool to secure concessions and advance its strategic objectives. Iranian officials have repeatedly identified control over the strait as a core strategic objective and a key component of Iran’s long-term deterrence posture. Recognized control over the strait grants Iran substantial leverage over global trade, which it can use to extract political and economic concessions at its discretion. The US-Iran MoU requires Iran to “make arrangements using its best efforts for the safe passage of commercial vessels with no charge for 60 days only,” but notes that Iran will negotiate a joint Iranian-Omani management scheme with Oman and the other Gulf Arab states.[14]  Iranian officials have continued to emphasize that an “open” strait is one subject to joint Iranian-Omani management and will attempt to achieve joint Iranian-Omani management, possibly by coercing the Gulf Arab states.[15] Recent Iranian threats to keep the strait closed unless Israel ends operations in Lebanon further demonstrate the regime’s willingness to use the waterway as a strategic source of leverage (see above).

Iranian officials continue to signal that the regime will charge “fees” in the long-term for vessels that want to transit the strait, which is part of the broader Iranian effort to maintain long-term control over the strait. The MoU allows for a resumption of fee collection after 60 days. Iranian parliamentarian Saeed Ajorlou stated on June 18 that the agreement only prohibits Iran from charging fees during the initial 60-day period, according to clause 5, and implied that the regime may resume “fee” collection afterward.[16]  IRGC-affiliated similarly stated on June 15 that Iran would suspend fees for 60 days but intends to reinstate them once that period ends.[17] Iranian officials have consistently characterized these charges as “service fees” rather than transit tolls, arguing that vessels therefore continue to have “toll-free” passage. The United Nations Convention on the Law of the Sea (UNCLOS) does not permit states bordering international straits to restrict transit passage or impose charges for the right to transit, however.[18] The Strait of Hormuz is an international strait, not territorial waters, and Article 26 of UNCLOS–which permits fees in territorial waters–therefore does not apply. The regime’s explicit intention to charge “fees” over the long term not only violates international law but also demonstrates that the regime views the strait as a tool through which it can exert control and extract benefits. Iran’s efforts to charge fees come at a time when Iran faces severe economic challenges and needs resources to rebuild its military and defense sectors following the war.

Iranian Supreme Leader Mojtaba Khamenei appears to be trying to avoid responsibility for the US-Iran MoU. Mojtaba released a written statement on June 18 regarding the US-Iran MoU.[19] Mojtaba stated that he authorized the MoU but emphasized that he had “a different opinion in principle.”[20] He added that Iranian President Masoud Pezeshkian and the Supreme National Security Council (SNSC), of which Pezeshkian is chairman, are responsible for protecting Iran‘s interests and preserving the Axis of Resistance. Placing responsibility with the president is almost certainly an effort to evade responsibility for any possible failures that may result from the MoU or the negotiation process.[21] The SNSC is Iran’s highest national security and foreign policy decision-making body.[22] Mojtaba added that Pezeshkian told him that Iran will not submit if the United States makes “excessive demands.”[23] Mojtaba also highlighted that future in-person negotiations will not mean that Iran accepts the “enemy’s” view.[24] Mojtaba’s statement comes after CTP-ISW previously assessed that Iranian regime factions have competed over the scope and aims of negotiations.[25] Mojtaba’s emphasis that Pezeshkian and the SNSC hold responsibility for the MoU appears to be a reaction to domestic pushback against the deal and part of a broader regime effort to manage internal concerns about the MoU’s implementation.