Threat of Strikes on Iranian Nuclear Facilities and Rising Tensions in the Strait of Hormuz and the Red Sea: A Geopolitical Risk Analysis

Executive Summary

Following the failure of regime change after the February 2026 U.S.-Israeli airstrikes on Iran and the expiration of the Islamabad Memorandum, the situation has shifted to a phase where both the U.S. and Iran are mutually targeting oil tankers. President Trump has publicly warned of potential further strikes on Iran's 'Pickaxe Mountain' nuclear facility, but constraints on U.S. interceptor stockpiles and domestic political pressure are acting as a ceiling on escalation. The most likely scenario over the next 4-8 weeks is the continuation of low-intensity clashes and sporadic escalation (50% probability), while a full blockade of the Strait of Hormuz or a dramatic de-escalation is considered less likely. South Korea needs to prepare for potential U.S. requests to join escort coalitions, participate in sanctions, or provide material support. A selective response is required, focusing on finding common ground through lower-level cooperation such as intelligence sharing and maritime security collaboration. Concurrently, Seoul must establish a contingency-based response framework that does not rely on a single scenario by diversifying crude oil import sources, assessing exposure to secondary sanctions, and maintaining a constant state of readiness in its emergency response systems for personnel and assets in the region.

I. Situational Analysis

Threat of Strikes on Iranian Nuclear Facilities and Rising Tensions in the Strait of Hormuz and the Red Sea: A Situational Analysis

1. Background and Developments

The starting point of the current crisis was the U.S.-Israeli airstrike on Iran on February 28, 2026 [2][8]. Supreme Leader Khamenei was killed in the strike [2]. However, contrary to Israel's intentions, the Iranian regime itself did not collapse [2]. When the goal of regime change was not achieved even after six months of military operations, the United States shifted its strategy toward seeking an exit through economic warfare [2][6].

On June 26, President Trump and the Tehran government signed the 'Islamabad Memorandum' [2][6][4]. It stipulated an immediate and permanent cessation of military actions on all fronts [2][6]. The memorandum expired on August 17 [4]. Following its expiration, Iran shifted from a defensive to an offensive posture, asserting its control over passage through the Strait of Hormuz by force [4][6]. In response, President Trump made statements that effectively demanded Iran's surrender, defining the Strait of Hormuz as 'U.S. territory' [4].

On August 30, the U.S. struck a launch site on Larak Island [6][11]. Iran immediately retaliated against U.S. military bases in Jordan and the UAE [6][10]. This broke a nearly month-long lull in hostilities [6][11][13]. U.S. stockpiles of THAAD and Patriot interceptors are reportedly depleted by at least 38% and up to 65%, respectively [6]. Despite these physical constraints, the United States is maintaining its hardline stance [6].

2. Current Situation

In September, the conflict shifted to a phase where both sides are targeting oil tankers. To deter Iranian attacks on commercial vessels, President Trump approved a new 'tanker-for-tanker' policy, and the U.S. military struck two Iranian government-owned tankers for the first time [5]. The U.S. military then conducted large-scale additional airstrikes within two days, and Iran responded by launching missiles and drones at U.S. bases in the Middle East [5][10].

On September 5, the U.S. military announced it had struck and destroyed three Iranian oil tankers. The stated reason was that a U.S. Navy warship had been attacked with a missile [15][17]. The U.S. military warned it would "destroy Iran's limited and exposed oil fleet" if necessary [15]. Prior to this, Iran's Islamic Revolutionary Guard Corps (IRGC) claimed to have attacked several vessels it identified as being linked to the United States. The IRGC stated that its naval forces had targeted "three oil tankers in unauthorized shipping lanes in the Strait of Hormuz" and "three vessels linked to the child-killer America," and issued a warning to other ships [1].

Amid these developments, President Trump publicly warned of a potential further strike on the 'Pickaxe Mountain' nuclear facility, located near the Natanz uranium enrichment site [3][7]. Pickaxe Mountain is known to be a highly fortified facility with two deep tunnel complexes [3]. A day earlier, President Trump had attempted to downplay the conflict as "small potatoes," but he is now observed to have shifted his stance back toward resuming combat [15]. While the U.S. government publicly maintains that the situation is not a 'war,' it is simultaneously intensifying airstrikes, sanctions, and its maritime blockade [7].

Iran is responding with harsh rhetoric. A government official in Tehran told Reuters that the recent engagement was "limited and controlled," but warned that any further attacks would be met with a response "dozens of times stronger" [16]. There have also been reports of a large funeral held after a missile struck a wedding hall in southern Iran, causing numerous casualties [7][10]. This is fueling anti-American sentiment within Iran.

3. Key Actors and Positions

United States (Trump Administration): Has reaffirmed that preventing Iran from acquiring nuclear weapons is its top priority and has officially ruled out the possibility of negotiations [2]. President Trump has personally issued repeated warnings to "hit harder" [11][13][14], while simultaneously messaging that the current conflict will not be prolonged [14]. This can be interpreted as a dual signal reflecting domestic political pressures, namely rising oil prices and declining approval ratings [8]. The Secretary of the Treasury has vowed to continue the pressure campaign to cripple Iran's economy [9].

Iran (IRGC and Government): Views its control over passage through the Strait of Hormuz as an asymmetric lever directly linked to regime survival [4]. The IRGC continues to use shows of force at sea to gain negotiating leverage [1], while a government official has described the recent engagement as 'limited' but warned of a much higher level of retaliation in the event of escalation [16]. Internally, arguments for withdrawing from the NPT and distrust of the international inspections regime are reportedly gaining traction [2].

UN Security Council: A new draft resolution is acting as a factor exacerbating the nuclear standoff [1]. The level of Iran's backlash will likely depend on the specific strength of the resolution's content.

Regional Countries Hosting U.S. Military Bases (e.g., Jordan, UAE): Are becoming entangled in the conflict in an unwelcome manner as they become targets for Iranian retaliation [6][10]. These countries are in a dual position, serving as hubs for U.S. military operations while also being exposed to the risk of direct strikes from Iran.

4. Key Issues

The first issue is whether and when the threatened strike on the nuclear facility will be carried out. It is unclear whether President Trump's remarks about Pickaxe Mountain will lead to actual military action or remain mere rhetoric intended to apply pressure following the breakdown of negotiations [3][4]. The second issue is the speed at which the tanker-for-tanker exchanges are transitioning from economic warfare to military conflict. As the new 'tanker-for-tanker' rule of engagement is applied by both sides, the risk of accidental clashes at sea is increasing [5][15][17]. The third issue is whether the physical constraint of the United States' dwindling interceptor stockpile will act as a real deterrent to escalation [6]. Finally, a key variable for the future of the crisis is whether the draft UN Security Council resolution will create more room for international intervention or, conversely, provoke a hardline response from Iran and thereby fuel escalation [1].

II. In-Depth Analysis

Threat of Strikes on Iranian Nuclear Facilities and Rising Tensions in the Strait of Hormuz and the Red Sea: An In-Depth Analysis

1. Analysis of Root Causes

The root cause of the current crisis can be found in the unachieved objectives of the February 28 airstrike. The United States and Israel launched the strike with the goal of regime change [2][8]. Despite the death of Supreme Leader Khamenei, the Iranian regime survived [2]. With the regime itself remaining intact, a gap emerged between the military objective and the political outcome. This gap became the starting point for all subsequent phases of the crisis.

The Islamabad Memorandum was an attempt to bridge this gap [2][6][4]. However, the memorandum was a provisional measure that only halted military action without reversing the failure of regime change. When the memorandum expired on August 17, the underlying conflict structure that had been papered over was re-exposed [4]. Iran's attempt to reclaim control over passage through Hormuz by force immediately after the memorandum's expiration is linked to its need to shift from a defensive to an offensive posture for regime survival [4][6].

President Trump's statement defining the Strait of Hormuz as 'U.S. territory' should be understood in the same context [4]. Previous analysis has judged this to be less a declaration of territorial sovereignty and more a rhetorical move to exert psychological pressure on Iran following the breakdown of negotiations [4]. However, following this statement, the U.S. response did escalate to the physical act of striking tankers. The line between rhetoric and action is thus becoming increasingly blurred.

2. Structural Context

Political Structure

The domestic political calendar in the United States is acting as a variable that modulates the intensity of the crisis. The six-month-long conflict is weighing on President Trump's domestic approval ratings [8]. Rising oil prices are structurally exacerbating this pressure [8][13]. President Trump's shift from downplaying the conflict as "small potatoes" one day to moving back toward resuming combat the next [15] can be interpreted as an attempt to find a balance between escalation and de-escalation that is mindful of domestic public opinion. Iran, for its part, is exploiting this dual U.S. posture by pursuing a strategy of maintaining a certain level of military retaliation while not completely closing off channels for negotiation [16].

Within Iran, a structure is solidifying in which regime survival and a hardline response are seen as virtually synonymous. An Iranian official told Reuters that the retaliation for the Larak Island strike was limited and controlled, while also warning of a "dozens of times stronger" response to any further attacks [16]. The IRGC's claims of attacking tankers and ships also emerged in this context [1]. With a hardline response itself having become a means of proving the regime's legitimacy, there is little incentive for Iran to back down first.

Economic Structure

Before the conflict, the Strait of Hormuz was a shipping lane through which about one-fifth of the world's oil supply passed [8][4]. This route has remained under a de facto blockade for over six months [8][4]. The U.S. is responding with a maritime blockade of Iranian ports [9], entrenching a dynamic where both sides apply pressure by paralyzing the other's maritime economic activities. The new U.S. 'tanker-for-tanker' policy [5] and its warning to destroy Iran's tanker fleet [15] show that this dynamic is cycling from military conflict to a war of economic attrition and back to military conflict.

The fact that China is a major importer of Iranian crude oil is also an indispensable part of this structure [2]. Previous analysis suggests that the selective, rather than comprehensive, enforcement of U.S. sanctions is not unrelated to a calculation to avoid escalating conflict with China [2]. However, this also reveals the limits of the sanctions' effectiveness [2]. Iran's ability to endure a long-term conflict without being completely isolated economically is related to these gaps in sanctions enforcement.

Security Structure

The fact that the U.S. missile defense system stockpile is acting as a physical constraint reveals a structural vulnerability. Stockpiles of THAAD interceptors are reportedly down by at least 38%, and Patriot stockpiles by up to 65% [6]. That the U.S. maintains a hardline stance despite this physical attrition [6] suggests a gap between political necessity and military capacity. If this gap is left unaddressed, it cannot be ruled out that U.S. response capabilities could be exhausted more quickly than expected in an escalatory scenario.

Iran, too, treats the asymmetric lever of a Hormuz blockade as a card directly linked to regime survival [4]. Evidence that Iran has considered striking U.S. military bases in Europe [6] is a signal that it may not limit the geographic scope of escalation to the Middle East. Claims of attacks on ships near the Red Sea [1] should also be read as evidence that Iran is leaving open the possibility of the conflict's geographic expansion.

3. Comparison with Historical Precedents and Similar Cases

The current situation shows similarities to the 'Tanker War' of the 1980s Iran-Iraq War in its method of target selection. At that time, both sides chose to induce economic bleeding by attacking tankers associated with the opposing country rather than engaging in direct military confrontation. In the current crisis, the U.S. formalizing a 'tanker-for-tanker' policy [5] and the IRGC specifically designating U.S.-linked vessels as targets [1] structurally overlap with this precedent. However, the directness of intervention is greater than in the past, as the U.S. Navy has now gone as far as to directly destroy Iranian tankers [15][17].

A comparison can also be made with the 2019 incidents of tanker attacks in the Strait of Hormuz. At that time, there were disputes over who was behind the attacks, but it did not escalate into an official military engagement between the two sides. In contrast, in the current crisis, both sides have officially acknowledged their role as attackers [1][15][17], which suggests the threshold for escalation has already been lowered. Compared to the period of tension following the elimination of Commander Qasem Soleimani in 2020, where both sides sought an off-ramp after a one-off retaliation, the current situation shows weakened resilience, as the nearly month-long lull following the August 30 Larak Island strike has been broken [6][11][13].

4. Key Variables Shaping Future Developments

The first variable is whether the strike on Pickaxe Mountain is actually carried out. This facility, which President Trump has threatened, is a fortified underground site near the Natanz uranium enrichment facility, featuring two deep tunnel complexes [3]. An actual strike on this facility would be perceived as a direct blow to Iran's nuclear program capabilities, likely bringing internal pressure for a hardline response to its peak. Conversely, if the threat remains a warning, the current state of low-intensity conflict may persist for some time.

The second variable is the fate of the draft UN Security Council resolution. Amid observations that the draft resolution is intensifying the nuclear standoff [Summary], whether this draft proceeds to an actual adoption process or stalls due to disagreements among permanent members will be an indicator of the level of international intervention.

The third variable is the depletion rate of U.S. interceptor stockpiles. With THAAD and Patriot stockpiles already significantly reduced [6], continued engagement could bring about a point where these inventories substantially constrain U.S. capacity for escalation. Depending on when this point is reached, the range of U.S. military options could narrow.

The fourth variable is the survival of regional mediation channels, such as the one through Oman. Previous analysis has identified the collapse of the Omani mediation channel as a turning point toward a pessimistic scenario [4]. As long as this channel remains active, a phase of alternating negotiation and tension is likely to continue, but if the channel is severed, a crucial buffer for controlling escalation will be lost.