Soon after the United States and Israel launched air and missile strikes on Iran on February 28, Iran hit back by not only targeting Israel and U.S. allies in the Gulf with missiles and drones but also by blockading the Strait of Hormuz through unconventional means. In recent weeks, the U.S. has blocked ships from entering or leaving Iranian ports through a conventional blockade. As a result, the center of gravity of Gulf War 3.0 appears to have shifted from Iran to the Strait of Hormuz.
The Hormuz crisis has hit Asian economies the hardest. While some tankers have been hit as they attempted to cross the strategic waterway, others have managed to pass through without incident. Hundreds of ships are said to be sitting idle in nearby ports.
Geospatial Intelligence (GEOINT) expert Professor Y Nithiyanandam, who heads the Geospatial Research Program at the Takshashila Institution in Bengaluru, has been using AIS-based observation, satellite imagery, and other open-source tools to monitor developments in the Strait of Hormuz and its impact on India. In an interview with The Diplomat’s South Asia editor Sudha Ramachandran, Nithiyanandam said that the important question thrown up by the 2026 Hormuz crisis is not whether this vital waterway is open or closed but “who controls the terms on which it remains open.” A state does not have to shut down the entire strait to flex its muscles. All it needs to do is “to make those few critical lanes uncertain enough to undermine commercial confidence, insurance coverage, and scheduling reliability.”
In the past, people viewed the Strait of Hormuz as a waterway through which oil and gas passed, one that gave Iran, the country that controls it, a binary option — to keep the strait open or shut. You wrote that the 2026 Hormuz crisis has changed our understanding of the strait. How?
For decades, the Strait of Hormuz was viewed through a very binary lens: either it stayed open to global shipping, or Iran tried to close it through conventional military escalation. That mindset grew out of the Tanker War era (1984-1988), when both Iran and Iraq targeted commercial shipping in the Gulf and Western planners concluded that while Iran could disrupt traffic, it could not hold the strait against superior U.S. naval power over time.
The 2026 crisis upended that assumption. What Iran has shown is that it does not have to physically shut the strait or defeat the U.S. Navy to exercise meaningful control over Hormuz; it only has to make passage sufficiently uncertain. That is the core conceptual shift.
Rather than mounting a classic blockade, Iran leaned on geography and a toolkit of selective disruption: sea mines, drones, Automatic Identification Systems (AIS) suppression, Global Navigation Satellite System (GNSS) spoofing, and calibrated incidents that steadily eroded confidence in the safety of transit. The waterway remained technically open, but operationally degraded. Within weeks, maritime traffic collapsed by almost 95 percent – not because of sustained naval confrontation in the strait, but because shipowners, insurers, and seafarers no longer saw Hormuz as certainly navigable.
This produced the largest disruption to oil flows through a single chokepoint in modern history, and the shock was felt most sharply in Asia. Before the crisis, roughly 20 million barrels of oil and petroleum products transited Hormuz each day, along with over 112 billion cubic meters of LNG annually, much of it bound for China, India, Japan, and South Korea. India alone relied on the strait for around 45–50 percent of its crude imports and about 52 percent of its LNG. So, the crisis revealed something broader: the critical vulnerability is no longer primarily about Western naval access to the Gulf; it is about the fragility at the heart of Asian energy supply chains.
What 2026 made clear is that chokepoint control has outgrown the binary model entirely. Physical obstruction and digital interference now operate alongside something harder to counter — the deliberate management of uncertainty. The question is no longer whether Hormuz is open or closed. It is who controls the terms on which it remains open.
You have argued that “Iran did not try to ‘close’ the Strait of Hormuz in the traditional sense. It tried to change how the strait works.” Could you explain?
Iran’s approach in 2026 was more subtle. Rather than stopping every vessel, Tehran set out to redesign the operating logic of the strait. Passage became conditional, uncertain, and selective.
At one stage, ships were increasingly routed through a narrow corridor in Iranian‑controlled waters between Larak and Qeshm Islands, where authorities began demanding transit clearances and, for some categories of traffic, charging newly introduced tolls. These tolls were later formalized in Iranian domestic law, giving the regime a legal‑administrative framework for what began as a de facto “toll‑gate” system. Some vessels moved through under tacit understandings; others delayed their voyages, switched off tracking systems, rerouted, or avoided the corridor altogether.
During the ceasefire announcement around the 40th day of the war, Iran initially tried to present this new transit system as a joint Iran–Oman arrangement, with reports of roughly a $2 million charge per vessel to give it a veneer of regional consent and legality. Oman publicly pushed back, citing its obligations under international maritime law and distancing itself from the scheme. Within weeks, by about the 53rd day of the war, the language of co‑management had faded, but Iranian control remained in practice: ships relying on the Omani side of the traffic lanes also began to encounter pressure and risk. AIS‑based ship-tracking showed that the supposedly neutral bypass lane was no longer neutral at all, but a space where vessels were exposed if they tried to avoid Iranian‑managed routes.
The shallow Iranian shelf is well‑suited to mine‑laying and asymmetric interdiction, while the deeper Omani corridor is effectively the only viable route for Very Large Crude Carrier (VLCC)‑class tankers. That allows large commercial shipping to be compressed into predictable channels without a formal blockade.
Iran was not trying to close the Strait of Hormuz. It was trying to own the conditions under which it stayed open.
What are the insights you have drawn from satellite imagery/AIS data on the strategy adopted by ships from India, China, Japan, and South Korea to deal with the uncertainty in the Strait of Hormuz?
The AIS and other remotely sensed data revealed something striking very early in the crisis: the maritime system effectively split into two realities, “the visible sea” and “the actual sea.”
At one point, satellite‑based Synthetic Aperture Radar (SAR) data detected nearly 340 vessels operating around Hormuz, but only about 16 percent were broadcasting AIS positions. At the same time, more than a thousand vessels across the Gulf experienced GNSS spoofing, with electronic positions jumping implausibly to airports or inland infrastructure. The divergence between the AIS‑derived map and the picture emerging from radar, optical, and thermal imagery became a core intelligence story in its own right.
The crisis laid bare the growing limits of relying on AIS alone for maritime awareness. As more commercial vessels reduced transmissions, intermittently disappeared from public feeds, or deliberately operated “dark,” tracking activity in Hormuz became far more complex. Analysts increasingly had to fuse AIS with optical satellite imagery, SAR, thermal signatures, and port‑side observations just to get a partial operational picture. The picture itself had become the problem.
India showed perhaps the widest range of adaptations. Indian‑linked vessels alternated between naval‑escorted passages, AIS‑dark movement, extended waiting patterns in the Gulf of Oman, and selective use of the northern Larak–Qeshm corridor under apparent coordination with Iranian authorities. Indian shipping had effectively become strategic logistics — risk-assessed, escorted, or concealed, rather than simply dispatched. Some smaller Indian Class B vessels enjoyed a temporary advantage that larger tankers did not. While VLCCs were confined to deep‑water lanes under growing Iranian control, these shallow‑draught vessels could move closer to the Omani coast near the Musandam Peninsula, where enforcement was initially weaker. Several such vessels were tracked using this coastal route rather than the Iranian‑managed tanker corridor. By early May, however, Iranian attacks closer to the Omani side had pushed traffic on even this route down to near zero, as enforcement extended into the coastal lane as well.
China’s behavior was politically revealing. Despite Iran’s designation of certain traffic as “permitted,” even major Chinese‑linked vessels hesitated. Two large COSCO ships reportedly turned back near Larak Island despite earlier indications of clearance. That was a telling signal: it suggested that even politically favored states did not fully trust access guarantees. At the same time, China expanded the use of opaque ownership structures and so‑called “dark fleet” practices to keep energy flows going.
Japan’s response was the most deliberate. The late April transit of the Idemitsu Maru was not simply a commercial shipment – it was, in effect, a test of whether coordinated passage could be institutionalized. It appeared to pass that test. For Tokyo, the implication was uncomfortable: freedom of navigation had given way to negotiated navigation, and Japan had just participated in legitimizing that shift.
South Korea provided the clearest negative case. Unlike India or Japan, Seoul did not appear to have built a comparable coordination mechanism in the early phase of the crisis. The attack on the HMM Namu near UAE waters highlighted the risks facing vessels operating outside the emerging managed‑transit architecture.
Across these cases, a common thread is visible: none of the major Asian shippers could treat Hormuz as a simple open corridor anymore. Each had to find a different mix of naval coordination, electronic concealment, route choices, and political signaling just to keep cargoes moving. Taken together, these patterns tell a single story: Hormuz is no longer a neutral global common. Access now depends on where you stand with Tehran, whether you are willing to comply with its rerouting demands, and whether you have quietly negotiated your place in the new order. The waterway is still technically open. But the terms are Iran’s.
Why are countries like India that use VLCCs, at greater risk while plying the Strait of Hormuz?
VLCCs are highly efficient for moving crude, but their deep draught gives them very little routing flexibility inside Hormuz. Unlike smaller coastal vessels, they are effectively confined to the narrow deep‑water channels near the Musandam Peninsula, which makes their movement highly predictable.
That predictability is the vulnerability. A state does not need to close the entire strait; it only has to make those few critical lanes uncertain enough to undermine commercial confidence, insurance coverage, and scheduling reliability.
For India, the exposure is significant because nearly 40–45 percent of its crude imports still move on VLCCs through Hormuz. At the same time, the crisis showed that India did not simply sit still. It tapped Saudi Arabia’s East–West pipeline to Yanbu, used Omani ports such as Salalah, Sohar and Duqm as staging points, and engaged Gulf partners diplomatically to keep supplies flowing.
Yet the limits of these options also became clear. Omani ports were useful for holding patterns and smaller cargoes, and Yanbu provided a partial bypass stream, but none could match the scale of uninterrupted VLCC traffic through Hormuz. Even the East–West pipeline itself came under attack.
Workarounds exist, but none scale to the volumes Asian economies require. Hormuz thus remains irreplaceable, and India’s planners know it.
Chabahar and Gwadar ports lie outside the Strait of Hormuz. What does geospatial intelligence during the crisis show about traffic around these ports and the wider Gulf of Oman, including congestion at nearby ports in Oman and the UAE, and the naval posture in the region?
Chabahar and Gwadar sit on the Makran coast outside the Strait of Hormuz, so they were never substitutes for the strait itself. What the crisis showed was a wider spillover into the Gulf of Oman, where ship-tracking and maritime reporting pointed to congestion, waiting patterns, and rerouting around alternative ports and anchorages in Oman and on the UAE’s east coast.
Chabahar appears to have taken on a more visible role as ships waited offshore or adjusted routing, while Gwadar remained more limited by its physical capacity and narrower port profile. The more important point is that neither port was operating in isolation: they formed part of a broader belt of holding areas stretching across the Gulf of Oman, including ports such as Sohar, Salalah, Fujairah, and Khor Fakkan, which were reported to be under pressure from displaced traffic.
Both India and Pakistan stepped in to protect their own shipping. The Indian Navy increased its presence in the Gulf of Oman under Operation Urja Suraksha and escorted Indian-flagged vessels once they were out of Hormuz and the Gulf of Oman, making transit more managed than normal. Around the same time, the Pakistan Navy began escorting Pakistani merchant ships and tankers on its own sea lanes, with some escorts operating in the Gulf of Oman and on routes toward Karachi.
So, the geospatial story is not that Chabahar or Gwadar replaced Hormuz, but that the wider maritime space around Oman and the UAE absorbed some of the disruption, while navies and shipping companies adapted to higher risk.
