Iran Update, September 28, 2026

Data Cutoff: 2:00 PM ET

The Institute for the Study of War (ISW) and The Critical Threats Project (CTP) at the American Enterprise Institute are publishing updates Monday through Friday to provide analysis on the war with Iran and the broader Middle East. Weekday updates cover events from the past 24-hour period, whereas weekend updates are abbreviated and cover the Houthi-Saudi conflict and major breaking developments related to the war with Iran. 

Key Takeaways:

• Saudi and Yemeni government-aligned forces may be targeting senior Houthi and Iranian Islamic Revolutionary Guards Corps (IRGC) missile and drone experts and military commanders in order to degrade the Houthis’ ability to attack Saudi oil infrastructure, military bases, and vessels.
• Saudi and Yemeni government-aligned forces are likely attacking Houthi sustainment and logistics centers in order to weaken Houthi forces that are engaged in combat across several sectors in Taiz Governorate.
• Yemeni government-aligned forces have concurrently continued to engage Houthi fighters on elevated terrain overlooking the Bab al Mandeb Strait and the Red Sea coastal plain.
• US President Donald Trump rejected an Iranian proposal that largely resembles the terms of the June US-Iran memorandum of understanding (MoU) and does not appear to include any new Iranian concessions.
• Iranian efforts to threaten shipping in the Strait of Hormuz aim to compel the United States to accept Iranian demands and surrender.
• The terms of the Iranian proposal indicate that Iran remains unwilling to make serious concessions even as Iran faces deteriorating economic conditions due to intensified US economic measures.
• Iranian officials expressed concerns to anti-regime media that current Basij Organization Commander Hossein Taeb is attempting to establish an armed support base. These concerns point to broader dysfunction issues within the Iranian regime that are likely due in large part to the reduced presence or influence of the Supreme Leader, who has traditionally played a key role in managing competition among the regime's various factions.

Toplines

Saudi and Yemeni government-aligned forces may be targeting senior Houthi and Iranian Islamic Revolutionary Guards Corps (IRGC) missile and drone experts and military commanders in order to degrade the Houthis’ ability to attack Saudi oil infrastructure, military bases, and vessels. An independent Yemeni analyst reported on September 28 that unspecified forces conducted an “operation” targeting a senior Houthi missile force commander and two Houthi missile experts south of Sanaa City.[i] The analyst also claimed that the unspecified forces conducted a separate operation targeting an unspecified site in the al Sabeen area of Sanaa City, which has previously hosted Houthi command and control (C2) sites.[ii] International media reported that a large explosion of unknown causes occurred in Sanaa City on September 28, roughly around the time of the reported operations.[iii] It is unclear whether the explosion is connected to the reported operations, however. Saudi-led coalition forces have killed other Houthi and IRGC drone and missile experts and commanders in recent days, according to Yemeni and Saudi media.[iv]

Saudi and Yemeni government-aligned forces may be attempting to disrupt the Houthis’ C2 networks and eliminate the group’s drone and missile expertise, which could in theory disrupt the Houthis’ ability to coordinate attacks on Saudi Arabia and vessels in the Red Sea. The United States previously targeted and killed Houthi drone and missile commanders in strikes on Sanaa and other major Houthi-controlled cities during Operation Rough Rider in 2025, which sought to degrade the Houthis' ability to attack vessels in the Red Sea.[v] The Houthis' drone and missile capabilities based in Sanaa are currently more important to the group's strike campaign against Saudi oil infrastructure, rather than Houthi attacks on Yemeni government-aligned forces in Yemen.[vi] The Houthis typically use armaments such as small arms, artillery, and first-person view (FPV) drones that are better suited for ground combat in southwestern Yemen’s rugged terrain rather than deploying missile or long-range drone assets.

A Saudi-Yemeni government strike campaign targeting Houthi missile and drone experts and commanders will only temporarily inhibit the group's ability to coordinate attacks on Saudi territory, however. The Houthis presumably have been able to reconstitute some of their drone and missile capabilities following Operation Rough Rider in 2025 given that they have conducted numerous attacks on Saudi vessels, oil infrastructure, and military bases since July 2026.[vii] Decapitation strikes typically offer only a temporary opportunity to exploit disruptions to the enemy's C2 networks because most developed military organizations can replace killed commanders. The Houthis also control a de facto, albeit illegitimate, state in northern and western Yemen with extensive military and political command networks that can replace individual commanders.[viii] Short term C2 disruptions could, in theory, provide an opportunity for Saudi and Yemeni government-aligned forces to further degrade the Houthis’ capabilities and will to strike Saudi sites or continue their operations to expand Houthi territory in Yemen.

Saudi and Yemeni government-aligned forces are likely attacking Houthi sustainment and logistics centers in order to weaken Houthi forces that are engaged in combat across several sectors in Taiz Governorate. A Yemeni news aggregator reported on September 28 that Yemeni government-aligned forces conducted airstrikes targeting Houthi weapons depots in the vicinity of al Rubayi, which is adjacent to the main road linking Taiz City and the Houthi-controlled Red Sea port of Mokha.[ix] Saudi and Yemeni government-aligned forces also previously conducted airstrikes targeting Houthi food storehouses on the main ground line of communication (GLOC) between Taiz City and the Houthi-controlled Yemeni capital of Sanaa on September 27.[x] Attacks on sustainment centers and weapons depots reflect a Saudi-Yemeni government effort to weaken Houthi combat forces throughout Taiz Governorate. The Houthis are currently attempting to capture territory and disrupt Yemeni government GLOCs throughout Taiz Governorate as they secure adequate supply lines. These GLOCs are essential in sustaining the Houthis campaign to capture Taiz City, consolidate control over the Mokha-Taiz GLOC, and cut off the Yemeni government’s last remaining GLOC between Taiz City and Aden.[xi]

The Houthis also engaged Yemeni government-aligned forces in Jabal Habashi District, located immediately south of the Mokha-Taiz road, on September 27.[xii] The Houthis may intend to advance east through Jabal Habashi District in order to disrupt or sever the Taiz-Aden GLOC and prevent Yemeni government-aligned forces from sustaining forces in Taiz City and the immediate vicinity. This would constitute an effective Houthi encirclement of Taiz City, which would threaten Yemeni government control over a major population center and isolate a significant amount of Yemeni government-aligned forces and materiel.[xiii]

Yemeni government-aligned forces have concurrently continued to engage Houthi fighters on elevated terrain overlooking the Bab al Mandeb Strait and the Red Sea coastal plain. The Yemeni government-aligned Southern Giants Brigades repelled several attempted Houthi advances in the vicinity of Jabal Kahbub, which is a mountain range that overlooks the Red Sea coastal plain about 30 kilometers north of the Bab al Mandeb Strait.[xiv] The Southern Giants Brigades published several videos of their forces conducting anti-tank guided missile (ATGM) and bomb-drop drone attacks on Houthi vehicles and positions during these attempted advances on September 27 and 28.[xv] A US-based Yemen analyst also reported on September 28 that the Houthis have engaged Yemeni government-aligned forces in particularly heavy combat in areas on the Taiz-Lahij Governorate border since September 25.[xvi] CTP-ISW has observed and reported on heavy combat between Houthi fighters and Yemeni government-aligned forces in these areas in recent weeks.[xvii] The Houthis likely seek to capture Jabal Kahbub and other elevated terrain in southwestern Taiz Governorate in order to deny Yemeni government-aligned forces favorable positions that could threaten Houthi control over the coastal plain.[xviii] A sustained Yemeni government force presence at Jabal Kahbub and on other elevated terrain in southwestern Yemen could permit Yemeni government-aligned forces to attack Houthi fighters and positions near the Bab al Mandeb.

US President Donald Trump rejected an Iranian proposal that largely resembles the terms of the June US-Iran memorandum of understanding (MoU) and does not appear to include any meaningful Iranian concessions. Iran reportedly sent a ceasefire proposal to US officials via Qatari mediators on September 16.[xix] The Iranian proposal called for a complete ceasefire and for the United States to lift the US blockade on Iranian ports, unfreeze billions of dollars of frozen Iranian assets, and end US sanctions on Iranian oil.[xx] Iran would “re-open“ the Strait of Hormuz to some commercial traffic after seven days and Iran and the United States would resume nuclear negotiations, according to Iranian Foreign Affairs Minister Abbas Araghchi.[xxi] This proposal, as rendered by Western media, does not include any new meaningful Iranian concessions. The proposal bears strong resemblance to the MoU that the United States and Iran signed in June 2026.[xxii] Iran committed to open the Strait of Hormuz to toll-free passage for 60 days in exchange for the United States lifting the US naval blockade under this agreement. The United States and Iran committed to negotiate a final deal within 60 days that would address the release of frozen Iranian funds, elimination of US sanctions on Iran, and a nuclear agreement.[xxiii] The Iranian offer to ”open” the strait after seven days does not necessarily mean that Iran would relinquish control over the strait, given that Iran has not indicated that it would relinquish its broader claims over the strait or abandon its effort to regulate maritime traffic. The requirement under the June 2026 MoU that Iran re-open the strait effectively advanced Iranian objectives by allowing Iran to briefly ”re-open” the strait in a way that retained Iranian management over the strait through the Persian Gulf Strait Authority (PGSA). The PGSA is an organization that Iran established to formalize its control over the strait and force commercial vessels to pay tolls and coordinate their movements with Iran.[xxiv] Two regional officials separately told the Associated Press on September 28 that Iran’s proposal would reopen the strait under a temporary shipping management arrangement that Iran is discussing with Oman.[xxv]

President Trump publicly stated on September 26 that he rejected Iran’s proposal. Araghchi noted a day later that US-Iran mediators had not yet formally conveyed the United States’ rejection and that Iran was waiting for a clear US position before determining its next steps.[xxvi] An unspecified official briefed on the negotiations told Reuters on September 28 that Qatari mediators expected to hold separate talks with Araghchi and US representatives on September 28 or 29 over an amended version of Iran’s proposal.[xxvii] The source did not provide any details on how the amended proposal differs from the original version, however.[xxviii]

The terms of the Iranian proposal indicate that Iran remains unwilling to make serious concessions even as Iran faces deteriorating economic conditions due to intensified US economic measures.  Increasingly restrictive US economic measures and the US naval blockade are restricting Iran’s access to oil revenue, hard currency, and external financial networks.[xxix] New aviation restrictions have further isolated Iran by cutting Iranian airlines off from several neighboring countries.[xxx] Unspecified Iranian experts told the New York Times on September 27 that growing economic despair has alarmed regime leaders, who remain concerned about renewed nationwide unrest.[xxxi]  US measures and pressure so far have not pushed Iranian decisionmakers to make major concessions, however. Regional government officials in contact with Iranian officials told the Wall Street Journal on September 27 that Iranian leaders believe Iran can withstand a prolonged blockade.[xxxii] The Wall Street Journal referenced the IRGC’s oversized presence in regime decision-making, which is consistent with CTP-ISW’s assessment that IRGC Commander Major General Ahmad Vahidi dominates regime decision-making.[xxxiii] Hardliners, including Vahidi and his allies, appear willing to absorb greater economic costs than pro-concession officials in order to achieve key Iranian war aims, such as preserving Iran’s claims over the strait.[xxxiv]

Iranian efforts to threaten shipping and attack US forces in the Strait of Hormuz are part of a regional campaign that aims to coerce the United States to surrender to Iranian demands. The IRGC claimed that it conducted 19 attacks on vessels on September 26 and 27.[xxxv] Iranian media provided no evidence to substantiate these claims, and CTP-ISW has not observed evidence that these attacks occurred. The Iranian claims, regardless of their veracity, likely seek to create an informational effect that increases shipping companies’ risk perceptions of transiting the strait without Iranian permission.  The PGSA similarly warned vessel owners and charterers on September 26 against using routes that Iran considers unauthorized and threatened to impose future passage restrictions on companies that violate Iranian procedures.[xxxvi]  These Iranian intimidation efforts come as the rate of traffic through non-Iranian-controlled routes in the strait has increased, likely due in large part to US efforts to restore the freedom of navigation in the strait.[xxxvii] Iranian informational efforts to intimidate shipping companies and keep oil prices high may reflect Iranian operational constraints on its ability to attack vessels in the strait, as CTP-ISW recently assessed.[xxxviii]

Iran has also attacked US naval forces as a line of effort within this campaign, likely to degrade the United States’ willingness and ability to continue enforcing the US naval blockade on Iranian ports.[xxxix] Three US officials told NBC News that an Iranian anti-ship cruise missile struck a vessel in the Strait of Hormuz on September 14 and injured eight US Marines.[xl] Iran likely calculates that raising the military and political costs of enforcing the blockade will weaken US willingness to sustain blockade enforcement and ultimately pressure the United States to end the blockade.

Iranian officials expressed concerns to anti-regime media that current Basij Organization Commander Hossein Taeb is attempting to establish an armed support base that could be used to target political opponents. An Iranian government official with close ties to the IRGC told anti-regime outlet Iran Wire on September 24 that Taeb’s revival and expansion of the Basij’s Janfada Campaign has generated dissatisfaction among senior Iranian government officials, clerics, and even IRGC commanders.[xli] The Janfada (“Those Who Sacrifice Their Lives”) Campaign is a Basij recruitment and mobilization initiative designed to bolster domestic support for the regime during wartime. ^[xlii] The regime reportedly launched the campaign in 2025 during the 12-Day War and revamped it in late March 2026 in an effort to recruit members of the Iranian population to help the regime defend against foreign attacks and maintain internal security.[xliii] Taeb revived and expanded the campaign in September 2026.[xliv] The campaign mobilized volunteers to hold a rally in Tehran on September 18 that state media claimed involved hundreds of thousands of participants.[xlv] CTP-ISW previously assessed that the recent Janfada exercise likely intended to demonstrate to the domestic population the regime’s capacity for mass mobilization within Iran and deter social unrest.[xlvi]

The Iranian government official claimed that Taeb added weapons training as a component of the Janfada Campaign in a concerted effort to exert influence over other branches of the regime.[xlvii] The regime opened a military training center in Imam Hossein Square in Tehran on September 23 that will train Janfada volunteers to use weapons and defensive equipment under Basij supervision.[xlviii] The government official cited concerns that Taeb could use trained participants as a part of an effort to bolster his own personal power within the regime, likely referring to a theoretical scenario in which Taeb is able to use supporters to threaten or pursue political rivals.[xlix] Concerns about Taeb attempting to exert influence over other components of the regime are consistent with Iranian officials’ recent suggestions to the New York Times that Taeb may have bypassed the authority of IRGC Commander Major General Ahmad Vahidi during a decision to attack civilian vessels in July 2026.[l]   

A former IRGC member told Iran Wire on September 28 that Taeb aims to prevent the selection of a new supreme leader and preserve Mojtaba's position through the Janfada Campaign.[li] Taeb has close ties to Mojtaba and was part of Mojtaba's inner circle that reportedly pushed his election to the position of supreme leader in March 2026.[lii] Taeb reportedly claimed that Mojtaba approved his plans for the Janfada Campaign.^[liii] Iran Wire reported on September 24 that Iranian regime officials from various factions are dissatisfied with Mojtaba as supreme leader.[liv] The former IRGC member claimed that some factions are considering reelecting a new supreme leader following the cessation of hostilities with the United States.[lv] The former IRGC member argued that certain IRGC- and Basij-linked actors are using the current leadership situation—likely referring to Mojtaba‘s absence—to advance their own interests.[lvi]

Iranian officials' concerns, as reported by Iran Wire, point to broader dysfunction within the Iranian regime that is likely due in part to the reduced presence or influence of the Supreme Leader, who has traditionally played a key role in managing competition among the regime's various factions.[lvii] Two unspecified ”regime insiders“ told Iran Wire on September 28 that officials and IRGC commanders believe the current arrangement under Mojtaba Khamenei is "unsustainable" and is "actively weaken[ing] the system."[lviii] Mojtaba has not made a public appearance since the start of the war on February 28, when he was severely injured in an Israeli airstrike that killed his father Ali Khamenei.[lix]  The former IRGC member said that Mojtaba’s orders reach Iranian officials through intermediaries, which creates uncertainty and reduces trust among Iranian officials.[lx] A source connected to clerical circles in Qom said that many senior officials, including members of the Assembly of Experts—a  body in charge of electing the supreme leader—are waiting for conditions to stabilize so that a new supreme leader can be selected.[lxi] Iranian anti-regime media and Western media have reported that some Assembly of Experts members opposed Mojtaba’s election in March 2026 and that those within Mojtaba’s inner circle, including Taeb, pressured members to vote for Mojtaba.[lxii]

US and Partner Military Operations

Nothing significant to report.

Iranian Strike Campaign

• Assessed Iranian War Aims:
  • Secure international recognition of Iranian control over the Strait of Hormuz
  • Degrade the US ability and willingness to continue the war
  • Restore deterrence vis-à -vis the United States and its regional partners
  • Divide the United States and Israel from the Arab states

Nothing significant to report.

US-Iran Negotiations

See topline.

Iranian Domestic Affairs

See topline.

Lebanon

Israeli media reported on September 27 that the Israel Defense Forces (IDF) is reorganizing and fortifying its ground force presence in southern Lebanon.[lxiii] Israeli media reported that the IDF is consolidating its forces along the IDF’s so-called ”Yellow Line”—referring to the line that demarcates the IDF’s security zone in southern Lebanon—and has begun to construct “an extensive line of outposts” in southern Lebanon.[lxiv] Reports of IDF efforts to reorganize its ground forces in southern Lebanon coincide with IDF ground force reductions in Lebanon. The IDF announced on September 24 that it reduced its ground force presence in Lebanon from eight to six brigades after achieving certain operational successes against Hezbollah in southern Lebanon.[lxv]

Iraq

Iraqi Prime Minister Ali al Zaydi is likely attempting to balance between competing US and Iranian demands on Iraq by negotiating with the United States to exempt some flights between Iran and Iraq from the Iraqi government’s recent compliance with the US ban on Iranian flights. The Iraqi federal government and the United States have negotiated in recent days over granting a sanctions waiver for Iraqi Airways flights that carry Shia pilgrims between Iran and Najaf International Airport.[lxvi] Flights between Najaf International Airport and Iran resumed on September 28, which suggests that the United States and Iraq may have reached an agreement.[lxvii] Zaydi offered to provide safeguards, including ”rigorous screening,” to ensure that the Iranian regime does not use the flights to transfer weapons, illicit funds, or sanctioned individuals, according to an Iraqi official speaking to Western media on September 28.[lxviii]  Zaydi may view a limited waiver permitting religious flights as a way to compromise between competing US and Iranian pressure. The Iraqi federal government closed Baghdad and Najaf International Airports to Iranian planes on September 23 and 25, respectively, to avoid US sanctions on Iraqi airports and aviation companies.[lxix] Zaydi may have discussed the Iraqi government’s decision to close Baghdad Airport to Iranian flights with Iranian President Masoud Pezeshkian in a September 23 meeting at the United Nations.[lxx] CTP-ISW assessed on September 24 that the Iranian regime is likely concerned about the Iraqi federal government’s cooperation with US efforts to target Iran’s sanctions evasion networks.[lxxi]

 Zaydi may have also attempted to secure exemptions for some Iranian flights in response to Iranian-backed Iraqi actors’ backlash to the decision to close Iraqi airports to Iranian flights. The announcement that the Iraqi government was negotiating with the United States to obtain exemptions came after several Iranian-backed Iraqi political actors, including Asaib Ahl al Haq-affiliated First Deputy Parliament Speaker Adnan Faihan, issued separate statements on September 26 that condemned and called for a reversal of the Iranian flight ban.[lxxii] The Iranian-backed Badr Organization also reportedly led a protest in Baghdad to demand that the Iraqi government reverse its decision, according to Iraqi media on September 28.^[lxxiii] Iranian-backed Iraqi militia Harakat Hezbollah al Nujaba supporters similarly demonstrated in front of Najaf International Airport on September 28.[lxxiv] Zaydi may also calculate that a waiver that allows some flights between Iran and Najaf International Airport may partially satisfy the militia’s demands and limit militia escalation over this issue.

Arabian Peninsula

See topline.