Nearly four weeks into Operation Epic Fury, US President Donald Trump says Washington is talking to Tehran, a claim Iran rejects, while the US has quietly moved thousands of troops toward the Middle East. What began on February 28 as a joint US-Israeli air campaign has quickly become the biggest US troop deployment to the region since the Iraq War.

What the air and sea campaign looks like

According to US Central Command, the air offensive has struck more than 9,000 targets across Iran. Those hits reportedly hit sites linked to former Supreme Leader Ayatollah Ali Khamenei, IRGC command centres, ballistic missile and drone production facilities, and naval assets. US officials also say more than 140 Iranian vessels were damaged or destroyed.

Iran has answered with near-daily missile and drone attacks on Israel, Gulf Arab states and US bases, and has effectively closed much of the Strait of Hormuz to commercial shipping. That narrow waterway handles roughly 20 percent of global traded oil, so closing it raises the strategic stakes.

Why the US is moving more ground forces

Washington says the reinforcements are meant to increase operational options. In recent weeks the Pentagon ordered about 2,000 soldiers from the US Army 82nd Airborne Division to deploy to the region. That contingent joins two Marine Expeditionary Units already being routed to the Gulf from opposite sides of the Pacific.

US officials, including Defence Secretary Pete Hegseth, said CENTCOM requested the reinforcements. Separately, US Secretary of State Marco Rubio told a congressional briefing that the US may need to secure nuclear material inside Iran, saying at one point that "people are going to have to go and get it," without naming who would do that.

So far, no ground invasion has been authorised. But the mix of amphibious Marine forces, elite Army paratroopers and a division-level command shape a broader set of military options than were available before.

Three forces, one theatre

The reinforcements coming to the Gulf fall into three distinct groups with different origins and timelines.

  • Tripoli Amphibious Ready Group: Centered on the America-class assault ship USS Tripoli and the 31st Marine Expeditionary Unit (MEU). Ordered out of Sasebo, Japan, on March 13, it transited the Strait of Malacca and was at Diego Garcia by March 23. It is expected to reach the CENTCOM area by late March or early April.
  • Boxer Amphibious Ready Group: Built around the Wasp-class assault ship USS Boxer and the 11th MEU, based in Southern California. The group left San Diego on March 19 to March 20. At roughly 22,200 km to the Gulf, it is not expected before mid-April at the earliest.
  • 82nd Airborne Division contingent: About 2,000 soldiers from the division's Immediate Response Force at Fort Bragg, North Carolina, were ordered to deploy. This brigade-sized element is a rapid-response formation that can arrive fast but without heavy armor at first.

Combined, the two Marine groups provide roughly 4,500 Marines and sailors. Together with the 82nd Airborne troops, nearly 7,000 additional US personnel have been sent to the region since the campaign began.

USS Tripoli and the 31st MEU

The USS Tripoli is an America-class amphibious assault ship, about 261 metres long and weighing 45,000 tonnes. It can operate as a light carrier for F-35B jets while also launching Marines by air and sea. The 31st MEU that sails with it includes around 2,200 Marines and sailors, built around a reinforced battalion with artillery and amphibious vehicles. The 31st MEU is permanently forward-deployed and has prior Gulf experience, including operations in 1998.

USS Boxer and the 11th MEU

The Boxer Amphibious Ready Group is centered on the Wasp-class USS Boxer and includes USS Comstock and USS Portland. It carries the 11th MEU, also about 2,200 Marines and sailors, plus roughly 2,000 sailors across the three ships. The Boxer deployment was accelerated by about three weeks from its original schedule.

The 11th MEU also has a long Gulf combat record, dating back to the 1990-91 campaign and operations in Iraq in the mid-2000s.

82nd Airborne Division

The 82nd Airborne provides the US Army's rapid forced-entry capability. The Immediate Response Force is a brigade-sized formation that can deploy worldwide in hours. The roughly 2,000 troops now ordered to the Gulf are trained for parachute assaults, seizing airfields and creating space for follow-on forces. They typically deploy without heavy armor at first, which constrains how long they could hold territory against sustained counterattacks.

What these forces could realistically do

Experts see the current build-up as oriented toward specific, short-term missions rather than a full ground campaign. Ruben Stewart of the International Institute for Strategic Studies noted that the 2003 invasion of Iraq used around 160,000 troops, while the current combat elements number only a few thousand. The forces arriving are designed for rapid raids, seizures of key terrain and limited-duration operations.

Analysts say three scenarios look most likely:

  • Seize or blockade Kharg Island. Kharg handles an estimated 90 percent of Iran's oil exports and was struck earlier in the campaign. Taking the island would be escalatory because of its economic importance.
  • Clear Iran's coastline to reopen the Strait of Hormuz. This is seen as the most realistic option. Amphibious and airborne units could secure maritime terrain and suppress threats to shipping.
  • Attempt to secure Iranian nuclear material. This would be the hardest and least realistic with the forces currently available because it would require a much larger and sustained ground presence.

Experts warn that strikes on major infrastructure like Kharg Island or nuclear facilities would carry the highest risk of triggering a broader Iranian response. Retired Admiral James Stavridis has cautioned that an assault on Kharg would likely face coordinated drone swarms, fast boats with explosives and missile fire, and that the island could be heavily booby-trapped despite being defensible.

Diplomacy running alongside military pressure

The military surge is happening at the same time as a patchwork diplomatic effort. Analysts describe the deployments as coercive leverage meant to strengthen the US bargaining position if talks proceed. But they also note the danger: as force levels grow, reversing course becomes harder and the risk of unintended escalation rises.

President Trump has said the US and Iran reached 15 points of agreement in talks, calling the discussions "very, very strong." Iran denies direct negotiations and says it received messages through third parties. Trump issued a 48-hour ultimatum for Iran to reopen the Strait of Hormuz or face strikes on power plants, then extended the deadline by five days as talks continued.

Pakistan has stepped forward as a potential intermediary. Pakistan's army chief spoke to President Trump, and Prime Minister Shehbaz Sharif held talks with Iran's president and later offered to host talks, pending agreement from both sides.

The bottom line

The US has moved a notable mix of amphibious forces and airborne troops into the Gulf, enough to carry out selective raids, secure maritime approaches and pressure Iran. The current posture does not look like the start of a sustained invasion. But because strikes on strategic infrastructure can provoke large responses, the situation remains risky. For now, the build-up is as much a diplomatic tool as a military one.