The Ground War Question: 3,500 Marines Have Arrived and the Pentagon Is Planning 'Weeks of Operations' in Iran

What Happened This Week

The USS Tripoli (LHA-7), an America-class amphibious assault ship, arrived in the U.S. Central Command area of responsibility on March 27, 2026, confirmed by U.S. Central Command in a statement posted to its official accounts. The ship serves as flagship for the Tripoli Amphibious Ready Group / 31st Marine Expeditionary Unit, carrying approximately 3,500 sailors and Marines, transport and strike fighter aircraft, and amphibious assault and tactical assets.

The Pentagon had approved the deployment in response to a CENTCOM request for additional support, according to Military Times. Defense Secretary Pete Hegseth signed off on the request as the Iran war entered its fifth week.

On Saturday, March 28, The Washington Post reported — citing U.S. officials — that the Pentagon is actively preparing for weeks of limited ground operations in Iran. The plans, which fall short of a full invasion, could involve:

• Raids by special operations forces
• Conventional infantry operations
• Possible seizure of Kharg Island, Iran's main oil export hub in the Persian Gulf
• Raids into coastal areas near the Strait of Hormuz to locate and destroy weapons targeting commercial and military shipping

According to the Post, one official put the potential timeline at "weeks, not months." Another official said the timeline could be "a couple of months." Both characterized the objectives as limited rather than a sustained ground occupation.

What the White House Says

White House press secretary Karoline Leavitt responded to the Post's reporting with a statement: "It's the job of the Pentagon to make preparations in order to give the Commander in Chief maximum optionality. It does not mean the president has made a decision."

As of Sunday, March 29, President Trump had not publicly commented on the ground operations report. The Pentagon did not respond to the Post's requests for comment before publication.

The Post report comes as the Trump administration has simultaneously been engaged in parallel diplomacy. Pakistan has been shuttling proposals between Washington and Tehran — most recently delivering a 15-point U.S. ceasefire plan to Iran. Pakistan's foreign minister said Sunday his country is prepared to host direct U.S.-Iran talks "in coming days." Foreign ministers from Saudi Arabia, Egypt, and Turkey gathered in Islamabad on Sunday for further discussions, though neither the U.S. nor Iran attended directly.

Iran's Response

Mohammad Bagher Ghalibaf, the Speaker of Iran's parliament and a former IRGC commander, responded on Sunday — either to the Post report or to separate intelligence his government holds:

"The enemy openly sends messages of negotiation and dialogue and secretly plans a ground attack. Unaware that our men are waiting for the arrival of American soldiers on the ground to set fire to them and punish their regional partners forever. Our firing continues. Our missiles are in place."

That statement was reported by Tasnim, an Iranian news agency with ties to the IRGC. Ghalibaf did not confirm or deny he was responding to the Washington Post report specifically. He had previously warned, on Wednesday March 25, that intelligence suggested "Iran's enemies" were planning to occupy an Iranian island and that any regional country assisting in such an operation would face targeted strikes on its "vital infrastructure."

Iran's navy chief Shahram Irani also stated Sunday that the USS Abraham Lincoln aircraft carrier — currently operating in the region — would be targeted "as soon as it comes within firing range." He specifically said Iran would "avenge the blood of the martyrs of the Dena warship," referring to an Iranian frigate sunk by U.S. forces on March 4.

What Kharg Island Is and Why It Matters

Kharg Island is a small island in the Persian Gulf approximately 25 kilometers off Iran's coast in Khuzestan Province. It is the origin point for roughly 90% of Iran's crude oil exports. Nearly all tankers carrying Iranian crude — whether bound for China, India, or other buyers — load at Kharg's T-shaped jetties.

The island hosts extensive oil infrastructure including storage tanks, loading terminals, a desalination plant, and an airstrip. Iran's IRGC maintains a garrison there. Seizing or destroying Kharg Island would effectively eliminate Iran's ability to export oil and generate the revenue funding its war effort.

U.S. military planners have studied Kharg for decades. A 2024 RAND Corporation assessment cited in Congressional testimony noted that seizing or neutralizing the island would require defeating layered IRGC coastal defenses, surviving Iranian drone and missile responses, and managing the international legal and diplomatic implications of seizing sovereign territory.

The island is also defended. Iran has positioned anti-ship missile batteries along its coastline, and the IRGC Navy has a documented history of mining operations in the Persian Gulf dating to the 1980s "Tanker War."

U.S. Troop Buildup: The Current Picture

The deployment of the USS Tripoli and its 31st MEU is one of several recent escalations in U.S. troop presence. As of March 29, here is what has been officially confirmed:

• USS Tripoli / 31st MEU: ~3,500 sailors and Marines, arrived March 27. Confirmed by CENTCOM.
• 82nd Airborne: Approximately 2,500 paratroopers are deploying to the Middle East. The 82nd is one of the Army's fastest-response units, capable of parachuting directly into contested territory. Reported by The New York Times and confirmed by Pentagon officials.
• USS Abraham Lincoln carrier strike group: Third U.S. carrier strike group in the region. Targeted by Iranian threats Sunday.
• Total U.S. military presence: Estimated at approximately 57,000 personnel across the theater as of mid-March, according to Politico, up from roughly 40,000 at the start of the war.

The Task & Purpose military news outlet reported that a second Marine Expeditionary Unit is also en route to the region, meaning U.S. amphibious assault capacity in the theater is doubling.

What Ground Operations Would Mean

The distinction between a "limited ground operation" and a "ground invasion" is significant — both legally and practically.

Limited operations (raids, special forces seizure of specific sites) could be authorized under the president's existing war powers and the Authorization for Use of Military Force the White House has claimed. They would not constitute an occupation, do not require congressional approval under the administration's legal theory, and could be presented as discrete military objectives.

A sustained ground occupation of Iranian territory — including Kharg Island — would be a different category of action. It would expose U.S. forces to sustained IRGC resistance, Iranian missiles, drone attacks, and improvised explosive devices in an unfamiliar operating environment. It would almost certainly trigger a broader regional response. Iran has already warned any Gulf country that hosts U.S. forces participating in such operations would face direct strikes on its infrastructure.

Legal experts speaking to Al Jazeera have noted that seizing Iranian sovereign territory would constitute an act of war triggering different international legal obligations than the current air campaign, and would complicate any future diplomatic resolution.

The Washington Post report emphasizes that Trump has not yet made a decision on whether to approve any of the ground operations plans. The Pentagon's preparation is described as providing the president with options, not as an imminent operation order.

The Diplomatic Track Runs Parallel

The military buildup is occurring simultaneously with the most active diplomatic period of the month-old war. On Sunday, Pakistan hosted a regional summit in Islamabad with the foreign ministers of Saudi Arabia, Egypt, and Turkey. Pakistan has previously delivered the U.S.'s 15-point ceasefire proposal to Tehran.

Iran formally rejected that proposal on March 26 and issued a five-condition counterproposal, including payment of war reparations and Iranian sovereignty over the Strait of Hormuz. The U.S. has not publicly responded to Iran's counterproposal.

Pakistan's foreign minister said Sunday that direct U.S.-Iran talks could happen "in coming days," though neither side has confirmed it publicly. Iran's parliament speaker's threat on the same day — calling U.S. troops "being waited for" — was delivered contemporaneously with the Islamabad diplomatic gathering, illustrating the dual-track nature of the current phase of the conflict.

The April 6 deadline — Trump's publicly stated date for striking Iranian power plants if Hormuz remains blocked — is one week away. The strait remains closed. The 15-point ceasefire has been rejected. Ground troops are arriving.