Houthi Attack on Four Saudi Cities and the Reignition of the Yemen War: Shifts in the Gulf Security Landscape and Policy Responses

Executive Summary

On September 8, Houthi rebels conducted simultaneous drone and missile strikes on four cities in southern Saudi Arabia, leading to the de facto collapse of the 2022 UN-brokered truce. The root cause of this incident is the Israel-Iran war, which began in February 2026 and has destabilized the Gulf security landscape. Iran is using the Houthis as a low-cost proxy to maintain its leverage in negotiations over the Strait of Hormuz. The Mecca Defense Pact, signed in August by Saudi Arabia, Türkiye, and Pakistan, failed to deter this attack as it is largely a symbolic signal lacking an automatic intervention clause, leaving Saudi Arabia to effectively respond alone. EAI assesses the baseline scenario (45% probability) to be the continuation of localized conflict and the entrenchment of a risk premium. However, a pessimistic scenario (35% probability), in which attacks expand to Saudi Arabia's eastern infrastructure if the dual chokepoint risk at the Straits of Hormuz and Bab el-Mandeb materializes, cannot be ruled out. South Korean companies should implement a phased response: transitioning to the permanent use of the Cape of Good Hope detour route, diversifying procurement sources in eastern Saudi Arabia, and conducting dual-track monitoring of both trends among Iranian hardliners and the effectiveness of the Mecca Defense Pact.

I. Situational Analysis

Houthi Rebels Attack Four Saudi Cities, Reigniting the Yemen War

1. Background and Developments

The starting point for the current crisis is not the Yemeni civil war itself, but rather the destabilizing effect of the Israel-Iran war, which began in February 2026, on the Gulf security landscape [3][6]. The Houthis, who control most of Yemen's densely populated areas and the capital, Sana'a, have resumed attacks targeting Saudi Arabia as an Iranian proxy [1][4].

A decisive turning point came in early July. The situation changed rapidly after two Iranian aircraft landed in Houthi-controlled territory [2][8]. This triggered the largest direct military engagement between Saudi Arabia and the Houthis since the 2022 UN-brokered truce [2][8]. The four-year-old Saudi-Houthi ceasefire effectively collapsed at this stage [7].

The Houthis declared a maritime blockade targeting Saudi Arabia, claiming to have attacked three vessels in the Red Sea [2][6]. They also targeted Saudi airports and oil infrastructure [2]. Yemeni government forces retaliated by striking the runway at Sana'a airport [2][6]. Riyadh conducted airstrikes on Houthi military and communications facilities on the coast of Hodeidah [2][6].

At this juncture, Saudi Arabia sought to secure its own means of deterrence. On August 7, Saudi Arabia, Türkiye, and Pakistan signed a joint defense pact in Mecca [3]. However, this agreement, being more of a symbolic signal that falls short of a NATO-style automatic intervention clause, failed to act as an immediate deterrent to the recent attack [3].

2. Current Situation

In the early hours of September 8, the Houthis launched simultaneous strikes on four cities in southern Saudi Arabia. They used drones and missiles to target a Saudi air base in Khamis Mushait and facilities of the state-owned oil company Aramco in nearby Abha [4][15]. The targets specified by the Houthis were Abha International Airport, King Khalid Air Base, and Aramco-related facilities in Abha and Jizan [15]. At least 73 people were reported injured, including children [10][14]. Saudi authorities and state media confirmed that the strikes caused fires and temporary operational shutdowns at the facilities [15].

The Houthis described the attack as a "wide-ranging operation deep inside Saudi territory" [1][4]. Reuters characterized it as a "major escalation" in the six-month-long Middle East war [1][4]. Al-Monitor assessed it as the "worst attack in years" [18], a description echoed by the Turkish newspaper Hürriyet [17].

Riyadh immediately vowed retaliation. The Saudi government threatened to respond to the attack with "massive retribution" [16]. Simultaneously, on the ground, Yemeni government forces are intensifying their advance against the Houthis [16]. The Swiss newspaper NZZ identified this incident as the first test of the effectiveness of the Mecca Defense Pact signed in August [16]. EAI's analysis is that since the pact is not an immediate automatic intervention mechanism, its practical deterrent effect on the Houthis has not yet been tested [3].

Chile's El Mercurio reported that over 300 people have died in recent fighting since the resumption of hostilities, and analyzed that the Houthis aim to control territory along the Bab el-Mandeb Strait [12]. The Sana'a Center also reported that the UN Special Envoy for Yemen warned that "the risk of a return to full-scale war is higher than at any time since the 2022 truce" [5].

3. Key Actors and Interests

The Houthi RebelsAs an Iranian proxy, the Houthis seek to gain negotiating leverage by controlling the Red Sea and the Bab el-Mandeb Strait [6]. The simultaneous targeting of Aramco facilities and a military air base in this attack can be read as an attempt to pressure both Saudi Arabia's oil export capacity and its air defense capabilities [15]. Having already seized control of most of Yemen's densely populated areas, the Houthis have a strong incentive to convert their military advantage into negotiating leverage [1][4].

IranIran is pursuing a low-cost strategy of pressuring Saudi Arabia through the Houthis without leaving direct traces of its involvement [3]. The landing of Iranian aircraft in Houthi territory in early July was an event that symbolically exposed this proxy war structure [2][8]. For Iran, the Houthis function as a separate channel of pressure during negotiations over the Strait of Hormuz [3].

Saudi ArabiaWith the collapse of the four-year truce with the Houthis, Saudi Arabia faces a dual burden. The first is the risk of direct strikes on its eastern infrastructure and oil export facilities [13]. According to analysis from the Sana'a Center, Saudi Arabia has long sought to de-escalate tensions with the Houthis to protect the East-West pipeline to Yanbu, which has become a critical channel for Saudi oil exports since the Hormuz blockade [13]. The second is the political pressure to prove the effectiveness of the Mecca Defense Pact [16]. Although Riyadh has vowed retaliation, its response has not significantly deviated from its existing approach of supporting ground operations by Yemeni government forces and conducting its own airstrikes [2][16].

The Internationally Recognized Government of Yemen (PLC)The PLC is countering the Houthis with actions such as striking the Sana'a airport runway [2]. However, its military forces are undergoing an internal reorganization following the January 2026 ousting of the UAE-backed Southern Transitional Council (STC) from Hadhramaut and Al Mahrah and the full withdrawal of UAE troops [11]. This adds uncertainty to the government forces' response capabilities.

International Shipping and Energy MarketsThese markets are also de facto stakeholders. The Red Sea-Bab el-Mandeb route has served as the remaining alternative channel with the Strait of Hormuz effectively destabilized. The recent attacks now threaten this route as well, materializing the risk of a dual chokepoint [6].

4. Key Issues

The first issue is the effectiveness of the Mecca Defense Pact. Whether the agreement with Türkiye and Pakistan will function as a genuine deterrent beyond its symbolic value will be an indicator of the intensity of Saudi Arabia's future response [3][16].

The second issue is the sustainability of the Red Sea shipping route. Amid the Houthis' declaration of a maritime blockade and claims of attacks on vessels [2][6], a scenario of rising risk premiums and the entrenchment of detour routes is considered more likely than a complete blockage [3].

The third issue is Iran's calibration of its level of intervention. As long as Iran maintains its leverage in the Hormuz negotiations, its proxy pressure via the Houthis is likely to continue. However, if negotiations break down, a scenario in which attacks expand to all of Saudi Arabia's eastern infrastructure cannot be ruled out [3].

The fourth issue is the direction of the internal front lines in Yemen. With government forces reorganizing after the ousting of the STC [11], whether the fighting around Sana'a airport and Hodeidah escalates into a full-scale war is directly linked to the possibility of a major conflict recurrence, as warned by the UN envoy [5].

II. In-Depth Analysis

Houthi Rebel Attack on Four Saudi Cities: An In-Depth Analysis

1. Analysis of Root Causes

The ostensible trigger for this attack was the landing of two Iranian aircraft in Houthi-controlled territory in early July [2][8]. However, this event was not the cause itself. The root cause lies in the Israel-Iran war, which began in February 2026 and has disrupted the deterrence equilibrium across the Gulf [3][6]. Iran is using the Houthis as a low-cost lever, allowing it to maintain its negotiating position in the Strait of Hormuz without leaving direct traces of its involvement [3]. From Iran's perspective, resuming attacks on Saudi Arabia is not a direct response to Israel or the United States. Instead, it is a method of imposing a risk premium on the entire region through a proxy force [3].

From the Houthi perspective, this escalation cannot be seen solely as a result of Iranian directives. The Houthis have their own goals of territorial expansion within Yemen. Chile's El Mercurio noted that the Houthis are aiming for effective territorial control along the Bab el-Mandeb Strait [12]. This is where Iran's proxy war interests and the Houthis' own domestic political and military objectives overlap. Because these two sets of interests align, the recent attack can be seen not merely as a demonstration to apply pressure, but as a genuine projection of military force.

2. Structural Context

Political Structure: The Multi-layered Actor Dynamics of the Yemeni Civil War

The Yemeni civil war is not a simple dichotomy of the Houthis versus the Yemeni government. In January 2026, a coalition of the internationally recognized Yemeni government forces, Saudi airstrikes, and local tribal forces ousted the UAE-backed Southern Transitional Council (STC) from Hadhramaut and Al Mahrah [11]. STC leader Aidarous al-Zoubaidi went into exile, and the STC was officially dissolved [11]. In the process, Emirati forces completely withdrew from Yemen [11]. This marked a turning point where the anti-Houthi camp in Yemen was reorganized under Saudi leadership. In other words, even before the current crisis, Saudi Arabia had been undertaking a restructuring to bring anti-Houthi forces in Yemen into its sphere of influence [11].

The purpose of this restructuring was to prepare ground forces for a renewed conflict with the Houthis. Sana'a Center expert Eleonora Ardemagni identified the reasons for Saudi Arabia's years-long attempts to de-escalate with the Houthis as preventing the recurrence of maritime attacks in the Red Sea and protecting the East-West pipeline to Yanbu [13]. This pipeline has emerged as a key channel for Saudi crude oil exports since the blockade of the Strait of Hormuz [13]. The strategic importance of this pipeline was a key reason why Saudi Arabia has tried to avoid a direct confrontation with the Houthis.

Security Structure: The Hormuz-Bab el-Mandeb Dual Chokepoint

Since the Iran-Israel war, the Strait of Hormuz has entered a state nearing a de facto blockade, forcing Saudi Arabia to reroute its crude oil exports through the Yanbu pipeline and the Red Sea [13]. However, with the Bab el-Mandeb Strait also becoming unstable due to the current crisis, a dual chokepoint scenario, where this detour route itself disappears, is materializing [6]. EAI has previously defined this as the "dual chokepoint risk, where the alternative shipping route itself is eliminated if Bab el-Mandeb becomes unstable while the Strait of Hormuz is under a de facto blockade" [6]. The fact that Aramco facilities were directly targeted in the recent attack demonstrates that the Houthis are indeed targeting this chokepoint structure [4][15].

A Gap in the Deterrence Structure: The Limits of the Mecca Defense Pact

On August 7, Saudi Arabia attempted to secure its own deterrent capability by signing a joint defense pact with Türkiye and Pakistan in Mecca [3]. However, this pact is "more of a symbolic signal that falls short of a NATO-style automatic intervention clause, making it difficult to function as an immediate deterrent against Houthi attacks" [3]. Indeed, the attack, which occurred just over a month after the pact was signed, exposed this limitation. The Swiss newspaper NZZ described the attack as the first test of the Mecca Defense Pact's effectiveness [16]. Without an explicit automatic intervention clause in the agreement, there is little incentive for Türkiye or Pakistan to become militarily involved in this crisis.

Spillover from the Maritime Security Vacuum: The Resurgence of Somali Piracy

Following the Iran-Israel war, international naval assets have been concentrated in the Strait of Hormuz and the northern Red Sea. As a result, the Gulf of Aden and the southern part of the Western Indian Ocean have become surveillance blind spots [9]. Exploiting this vacuum, seizures by Somali pirate groups from Puntland have markedly increased since April 2026 [9]. If the security situation in the Red Sea and Bab el-Mandeb deteriorates further due to the recent Houthi attacks, international naval attention could shift even more to the north, potentially deepening the security vacuum in the Gulf of Aden [9].

3. Comparison with Historical Precedents and Similar Cases

Comparison with the Period Before the April 2022 Truce

This attack is considered the largest direct military engagement between Saudi Arabia and the Houthis since the UN-brokered truce of 2022 [2][8]. Before the 2022 truce, the Houthis had a history of repeatedly targeting Saudi Aramco facilities and airports. The targeting of Abha International Airport, King Khalid Air Base, and Aramco-related facilities in the recent attack [15] is akin to a recurrence of this pre-truce pattern. The difference, however, is that this time there was a clear trigger—the confirmed landing of Iranian aircraft in Houthi territory [2][8]—making the degree of Iranian involvement more visible than before.

Continuity with the Red Sea Threats During the Gaza War

The current crisis is an extension of the pattern seen during the Gaza War, when the Houthis threatened the Red Sea-Bab el-Mandeb shipping route by targeting Israel-linked vessels [6]. At that time, global shipping lines also suspended Red Sea transits and opted for the Cape of Good Hope detour [6]. A similar rerouting of shipping lanes is likely to occur again following these latest attacks. The key difference, however, is that the current situation is unfolding within the broader conflict structure of the Israel-Iran war. Consequently, the political justification for vessel attacks has expanded from a connection to Israel to the broader Saudi-Iran proxy war dynamic.

The UAE's Withdrawal and the Shift to a Saudi-led Management System

The dissolution of the STC and the withdrawal of Emirati forces in January 2026 [11] show that the division of labor among Gulf states in the Yemeni civil war has converged into a Saudi-led system. Previously, the conflict was characterized by the diverging interests of Saudi Arabia and the UAE, each backing different proxy forces. In the current phase, this dual structure has been resolved, transitioning to a system where Saudi Arabia unilaterally manages the anti-Houthi camp. This also means that Saudi Arabia's burden of response has increased, as there is less room to share the military burden with the UAE as in the past.

4. Key Variables Shaping Future Developments

Trends Among Iranian Hardliners and the Trajectory of Hormuz Negotiations

EAI analysis identifies the Iran-Oman negotiations over the Strait of Hormuz as a higher-level variable in this crisis [3]. Given the structure in which Iran uses the Houthis as a bargaining chip, Iran's incentive to intervene via the Houthis could diminish if negotiations reach a resolution. Conversely, if the talks collapse, the probability of the "pessimistic scenario in which attacks expand to all of Saudi Arabia's eastern infrastructure" increases [3]. EAI analysis assessed the probability of this scenario at 30% [3].

The Test of the Mecca Defense Pact's Effectiveness

The form of support that Türkiye and Pakistan actually provide following this attack will be a test of the pact's practical binding power [16]. If their response is limited to symbolic statements, the Houthis and Iran will have an incentive to further increase pressure on Saudi Arabia. Conversely, if concrete military or intelligence support is confirmed, the Houthis' own calculus for escalation could change.

The Scale of Saudi Retaliation and Potential for Ground War Escalation

Riyadh has warned of “massive retaliation” for the attack [16]. Simultaneously, Yemeni government forces are intensifying their ground advance against the Houthis [16]. The UN Special Envoy for Yemen assessed the current phase as having “the greatest risk of a return to full-scale war at any time since the 2022 truce” [5]. The intensity of Saudi Arabia’s retaliation and the pace of the Yemeni government’s ground advance will be key variables determining whether the conflict escalates into a full-scale war in the coming weeks.

The Entrenchment of the Red Sea Risk Premium

The EAI baseline scenario considers “a rising risk premium and the entrenchment of detour routes” a more likely path than a complete blockade of the Red Sea, with an assessed probability of 50% [3]. If this scenario materializes, the rerouting of global shipping companies via the Cape of Good Hope is likely to solidify into a permanent operational model. This would mean the situation becomes a medium- to long-term structural cost rather than a short-term crisis.