"U.S. Amphibious Assault on Iranian Islands Unlikely to Have Strategic Impact" - Quincy Institute

Although reports have emerged that the United States is simultaneously floating the possibility of peace negotiations with Iran while also considering a "final blow" scenario involving the deployment of ground forces, analysts say that ground operations—such as amphibious landings or airborne troop insertions on Iranian islands in the Persian Gulf—are highly unlikely to yield any significant strategic effect.

The Quincy Institute, a U.S. think tank, stated this in an article titled "Limited US Ground Operations in Iran Will Not Shift the War’s Balance," published on its website on April 1 (local time). The Quincy Institute, founded in 2019, is a newer U.S. think tank that prioritizes "diplomatic solutions for peace" over military responses.

U.S. President Donald Trump has set 8:00 p.m. (Eastern Time) on April 6 as the deadline for negotiations with Iran.

The following is a summary of the main points.

There have been reports that the United States is considering limited ground operations in the Iran conflict. Among the operations under discussion are attempts to seize Abu Musa Island, the Greater and Lesser Tunb Islands, Larak Island, and Kharg Island in the Persian Gulf.

Serious doubts have been raised about the feasibility of such potential U.S. ground operations. Even if these uses of force were to succeed tactically, as with air campaigns, it remains highly unlikely that the Trump Administration would achieve its desired strategic effects. Limited ground operations alone would not be enough to force Iran to agree to an immediate ceasefire or to initiate early political agreements to end the war.

Moreover, the prospects of compelling the Iranian government to fully reopen the Strait of Hormuz before combat ends are even slimmer. Iran's control over the Strait of Hormuz is its most important leverage for pressuring for favorable terms to end the war.

Such limited ground operations are more likely to prolong and escalate the conflict rather than serve as a means to a rapid conclusion. These operations would substantially increase the resources required to sustain the war and could seriously undermine U.S. military readiness in other key national interest regions, particularly in the Indo-Pacific. Furthermore, this degradation in readiness would not be short-lived.

U.S. Considers Ground Operations on Iranian Islands

The United States is now seeking solutions to break a strategic deadlock that cannot be resolved by air power alone. Currently, the U.S. is considering an operation to capture three Iranian islands in the Persian Gulf—Abu Musa, Larak, and Kharg—using ground forces. Because the military and strategic value of these islands differs, it is not clear which one is the higher priority target. While Abu Musa (including the Greater and Lesser Tunbs) and Larak could be useful for controlling the Strait, they are not considered decisive, though they do carry clear operational value. In contrast, control of Kharg Island appears to be considered a form of economic counter-leverage against Iran, as the island serves as a major export hub handling 90% of Iran’s total oil exports.

The United States is currently conducting three ground force deployments to the Middle East. These include the Tripoli Amphibious Ready Group and the 31st Marine Expeditionary Unit (2,500 Marines), which arrived in the theater on March 27; the Boxer Amphibious Ready Group and the 11th Marine Expeditionary Unit (2,500 Marines); and 2,000 paratroopers from the 1st Brigade Combat Team of the 82nd Airborne Division. This force of 7,000 troops is in addition to the 50,000 U.S. troops already stationed in the Middle East. The U.S. is also reportedly considering sending an additional 10,000 troops.

The main combat mission of these three forces is to function as rapid response assault units. The U.S. Army’s 82nd Airborne Division specializes in parachute assaults. However, airborne troops are generally not the main force in forced-entry operations, as the equipment that can be dropped by parachute is limited, resulting in less firepower than traditional infantry. Moreover, the target islands are small, and in the extremely hostile environment of the Persian Gulf, it would be difficult to drop paratroopers accurately onto their objectives.

The Marine Expeditionary Unit (MEU), typically comprising 2,200 to 2,400 personnel, is the smallest form of the Marine Air-Ground Task Force (MAGTF). The MAGTF is traditionally designed as a combined arms task force capable of carrying out forced-entry operations—such as amphibious assaults—independently and without land bases. They can also conduct air assaults using MV-22 Ospreys or CH-53K King Stallions from amphibious assault ships. The MAGTF is particularly well-suited for operations that require projecting force from sea to land.

Seizing Abu Musa and Larak

Although Abu Musa and Larak have been reported as separate operations and objectives, both have historically been regarded as crucial for controlling the Strait. However, the growing lethality of Iranian missiles and drones has somewhat reduced their utility. According to reports, the Islamic Revolutionary Guard Corps (IRGC) has, since around March 13, effectively operated Larak as a "toll booth," demanding payments from ships to guarantee safe passage. The United States appears to be considering seizing these islands by force to reopen the Strait.

Tactically, the likelihood that the U.S. would attempt a traditional amphibious assault on any of these islands is very low, given the excessive risks. Iran’s anti-ship cruise missiles, ballistic missiles, and underwater drones can easily target the amphibious assault ships and landing craft needed to move Marines from sea to land. If Iran were to successfully mine parts of the Strait, the threat would only increase. Due to the threats posed by Iran to U.S. Navy surface vessels, the Abraham Lincoln Carrier Strike Group is operating in the Arabian Sea. In this context, the likelihood that the Navy can bring ships within the maximum launch range for amphibious assault vehicles—just 3,000 to 4,000 yards from the shore—to directly support an amphibious landing is low.

Therefore, airborne assault is considered the most likely method of insertion. Abu Musa is closer to the United Arab Emirates, making it much easier to deploy Marines there than to Larak. Larak is much closer to Iran’s southern coastline, just six miles east of the 579-square-mile Iranian island of Qeshm.

The ultimate difficulty does not lie in landing and occupying Abu Musa or Larak. While the assault force would likely come under fire from surface-to-air missiles and air defense drones, the real problem is holding the islands after they are seized. Without prepared fortified positions for cover, protecting the force—even with air support from nearby naval assets—would be a tremendous challenge. The Marines would be highly vulnerable to relentless Iranian ballistic missile and drone attacks launched from nearby islands like Qeshm or the Iranian mainland, severely limiting the ability to project power into the Strait. Logistics support would also be extremely challenging. A Marine Expeditionary Unit (MEU) can usually sustain itself for about 15 days, but after that, resupply becomes necessary. If Iranian threats persist at that point, any resupply attempt would be exposed to intense fire.

Therefore, it is unclear whether merely occupying Abu Musa and Larak would actually help reopen the Strait of Hormuz, especially if not as part of a broader operation. Satellite imagery suggests that Iran has deployed a significant number of anti-ship cruise missiles on Qeshm; unless the U.S. also seizes Qeshm, it will not have removed the threat posed by Iran’s capabilities in the Strait itself. More fundamentally, the primary threats to navigation in the Strait of Hormuz do not originate from military assets stationed on the islands, but from the entire southern Iranian coastline, which can launch ballistic missiles, cruise missiles, and drones. Although Iran has historically deployed radars and anti-ship cruise missiles on the islands, there are many other possible launch locations. In reality, while the Strait is the narrowest part of the waterway, ships must transit the entire Persian Gulf, and only a tiny minority of vessels are outside the shortest-range Iranian ballistic missile coverage, with the remainder all within the range of Iranian capabilities, including Shahed-136 drones with a range of 1,000 miles.

As the war has already shown, Iran’s missile and drone threats cannot be eliminated by aerial bombing alone. For example, a Shahed drone only requires a pickup truck as a launch platform, making it highly mobile and easy to hide. The terrain of Iran’s southern coast, dominated by the Zagros Mountains, makes it even more difficult to detect and destroy Iranian firepower from the air. On top of this, Iran has spent decades preparing defensive measures to avoid targeting. The Iranian southern coastline is 1,520 miles long—about the distance from Washington, D.C. to the eastern border of Colorado. To meaningfully suppress Iran’s missile and drone firepower across such a large area, the United States would require a much larger ground force, including assault units and logistics support.

The scale of this threat is one reason the U.S. Navy has until now avoided escort operations in the Persian Gulf—the risks are simply too high. At supersonic speeds, an anti-ship cruise missile can reach a vessel 30 nautical miles from shore in just 47 seconds. The Navy has already told shipowners that, given current resources, it cannot conduct escort operations, and even if it could, at best it could protect only 10% of normal traffic.

Seizing Kharg Island

Seizing Kharg Island would be much more difficult than Abu Musa or Larak. Kharg lies just 16 miles off the Iranian coast, 410 miles northwest of the Strait of Hormuz, and is roughly parallel to Kuwait. This geography gives Iran a significant advantage in supporting the island’s defense and interfering with U.S. resupply. Like Abu Musa and Larak, a traditional amphibious assault on Kharg is virtually impossible. Therefore, the assault force would need to launch an airborne assault either from amphibious assault ships in the Arabian Sea or from other U.S. bases in the Middle East.

The chances that the United States could achieve surprise in seizing Kharg are very low. Iran understands the island’s value as well as Washington does. The Islamic Revolutionary Guard Corps is already garrisoned there, and recent reports indicate that Iran is reinforcing its defenses, increasing troop levels, deploying additional man-portable air-defense systems, and laying anti-personnel and anti-tank mines, including along beaches where a U.S. amphibious assault might be attempted.

Kharg is a small island with an area of 7.7 square miles and, except for a small hill zone about 230 feet high at its southern tip, is mostly flat. The island’s center, Kharg City, is home to more than 8,000 civilians and has the only airfield. The significant civilian presence would make a clearing operation by U.S. forces much more difficult. However, it is unclear whether Iran would engage U.S. forces directly on the island or instead withdraw and continue attacking with ballistic missiles, drones, and other available firepower. Given the lack of cover on the island and its proximity to the Iranian coast, U.S. forces on Kharg would be extremely exposed.

Even if the United States succeeded in seizing and maintaining control of the island for a period, it is unlikely that occupying Kharg would provide the strategic leverage Washington seeks. While Kharg is Iran’s key oil export terminal, Iran also has other export hubs such as Jask Port, Lavan Island, Siri Island, and Qeshm. While none can match Kharg’s capacity, they are sufficient for Iran to maintain an emergency economic lifeline. Analysts believe these facilities could handle about 25% of Kharg’s throughput. Iran’s capacity to endure hardship is extremely high, and, especially given that oil is now selling at twice the prewar price, this lifeline alone is unlikely to force Iran to yield to U.S. pressure. Iran has previously suffered major disruptions to oil exports without giving in. For example, in 2020–2021, Iran’s oil exports fell below 250,000 barrels per day for several months, yet the government did not capitulate under increased pressure, even though normal output exceeded 3 million barrels per day at the time.

Seizing Kharg could also backfire strategically. Iran would likely intensify attacks on energy infrastructure across the Gulf, and the loss of Iranian oil production would further exacerbate already severe global oil supply pressures and price spikes. The United States and its partners appear to be even more sensitive to such variables than Iran. The Trump Administration has already acknowledged the seriousness of its predicament by unilaterally lifting some sanctions on Iranian oil. Iran might also prioritize attacks on civilian infrastructure, such as desalination plants. Therefore, the U.S. should not harbor the illusion that seizing Kharg would serve as a panacea that would turn the tide of war in its favor.

In Conclusion

The operations currently under consideration by the United States involving the use of ground forces are unlikely to help regain the initiative in the war. These operations entail serious tactical and operational risks as well as major strategic flaws. The United States must resist the temptation to invest further military resources in a conflict where it is difficult to achieve strategic objectives at an acceptable cost relative to other national priorities. Unpleasant as it may be, the U.S. should pursue a negotiated settlement that can prevent further losses and preserve its power and ability to fulfill alliance commitments to the greatest extent possible.

This content was produced with the assistance of AI translation services.