US–Israel–Iran War: Boots on the Ground?

Israel’s leadership adopted comparable objectives. Israel’s leadership, including Prime Minister Benjamin Netanyahu and Defence Minister Israel Katz, authorised strikes to prevent Iran from arming Hezbollah and Houthi proxies and to blunt Tehran’s capacity to threaten Israel’s borders. Analysts note that Trump’s rhetoric veered towards regime change, but official briefings emphasised military rather than political goals. The Modern War Institute cautions that regime change “without boots on the ground is very unlikely”.[2]

Forces in Place

United States

Before the war, about 40,000 US troops were stationed across Middle Eastern bases—Bahrain (home to the Fifth Fleet), Qatar’s Al Udeid Air Base (approximately 10,000 personnel), Kuwait’s Camp Arifjan and Buehring, Al Dhafra Air Base in the UAE, and installations in Iraq, Saudi Arabia and Jordan[3]. To prosecute the 2026 conflict, Washington surged its largest force since 2003: two aircraft‑carrier strike groups (USS Abraham Lincoln and USS Gerald R. Ford), more than a dozen other warships, B‑1 and B‑2 bombers, F‑22, F‑35, F‑15 and F‑16 jets, and refuelling tankers. Patriot and THAAD batteries were bolstered to defend against Iranian retaliation.[4]

Speculating ground action, the amphibious assault ship USS Tripoli, carrying nearly 1,800 Marines, has been deployed to the Indian Ocean.
The Tripoli is embarked with troops from the 31^st Marine Expeditionary Unit.
According to the US Navy data, the vessel can carry around 1,850 Marines along with a crew of about 1,200 sailors. Supporting it is the amphibious transport dock USS New Orleans, part of the Tripoli Amphibious Ready Group, which can accommodate an additional 700 Marines.
US President Donald Trump has indicated that American forces could target Iran’s Kharg Island, a critical hub handling nearly 90 per cent of the country’s oil exports. The 11^th Marine Expeditionary Unit’s USS Boxer amphibious group, comprising up to 2,200 Marines, has been directed towards the Middle East. Additionally, around 1,000 troops from the 82nd Airborne Division have reportedly been ordered to the region.[5]

Iran

According to the Global Firepower database, Iran fields approximately 610,000 active‑duty soldiers and 350,000 reservists, for a total military manpower of approximately 1.18 million. Approximately 350,000 troops serve in the regular army and 190,000 in the Islamic Revolutionary Guard Corps (IRGC); the Basij paramilitary adds about 220,000 personnel.[6] Iran’s ballistic‑missile stockpile is the region’s largest, its navy operates more than 100 fast-attack craft and 25 submarines, and it compensates for a modest air force (approximately 250 combat‑capable aircraft) with extensive drone programmes and underground missile bases. Iran’s air power and naval assets were largely destroyed in the opening days of the conflict.

Israel

The Israel Defense Forces (IDF) mobilised roughly 100,000 reservists to fortify its northern frontier and occupy positions in southern Lebanon, emphasising that there was no practical plan for a ground invasion of Iran.[7] The IDF has had three armoured and infantry divisions on the Lebanese border since the start of the Iran war, aiming to seize the entire area south of the Litani River and dismantle Hezbollah’s military infrastructure to neutralise Hezbollah’s rocket threat and push Iranian proxies away from its borders.[8]

Current Roles of Ground Forces

As of now, land forces have been relegated to supporting roles as leaders in Washington and Jerusalem reject a large‑scale invasion. US Joint Chiefs Chairman Dan Caine noted there is no plan to “roll 200,000 people in there and stay 20 years”, while Hegseth refused to rule out ground operations but insisted Washington was not seeking an open‑ended conflict.[9] Israeli spokesman Lt. Col. Nadav Shoshani reiterated that there is no practical idea for ground troops. Ground forces have been limited to these missions—border security along the Israel–Lebanon and Syria frontiers, where IDF infantry and armour occupy hilltops and conduct limited incursions to disrupt Hezbollah, protection of bases and shipping lanes, as US Marines and Army units guard regional installations and escort convoys to deter Iranian attacks on logistics hubs and Gulf shipping.

Requirements for a Full Invasion

Most analysts agree that achieving regime change by air and sea alone is improbable. The Arab Center, Washington D.C. notes that Iran’s mountainous terrain, dense population (approximately 90 million) and extensive militia network would necessitate hundreds of thousands of invading troops, cost trillions of dollars and likely provoke an insurgency worse than post‑2003 Iraq.[10]

The main prerequisites and challenges include:

1. Air and naval supremacy: Coalition forces have mostly neutralised Iran’s air defences, missile launchers and navy to secure supply lines. Ports and airfields in Kuwait, Bahrain, or Oman (or even Pakistan) would require expansion, and regional partners would need to allow staging areas—politically contentious requests.
2. Force levels and logistics: Given Iran’s size (roughly four times Iraq’s) and multiple axes of advance, military planners estimate 300,000–500,000 troops would be needed.[11] Secure lines of communication through mountains and cities would be vulnerable to guerrilla attacks.
3. Duration: While Trump initially predicted a four‑to‑five‑week air campaign, experts believe a ground invasion would require months or years of combat followed by prolonged occupation and nation‑building.
4. Humanitarian impact: Large‑scale operations would cause massive civilian casualties and displace millions. Israel’s limited incursion into southern Lebanon in March 2026 displaced 80,000 people in days; a campaign in Iran would be far worse.

When Ground Troops Might Become Necessary

Ground forces could become strategically important under three scenarios:

1. Securing nuclear facilities: If intelligence indicated Iran was on the verge of assembling a nuclear device in hardened underground sites, coalition forces might need to raid and secure those facilities, requiring air superiority and precise intelligence.
2. Stabilising border regions: Ground forces may be needed to protect civilians and dislodge proxy forces. Israel’s occupation of hilltops along the Blue Line demonstrates this role, and a wider conflict could draw troops into western Iran to block missile launches against Gulf allies.
3. Regime change: Should leaders decide that air and naval strikes cannot meet political objectives, they may consider a full invasion. The Modern War Institute notes that regime change is unlikely without boots on the ground,[12] but experts warn of enormous costs and unpredictable consequences.

Political and Strategic Ramifications

Deploying large numbers of ground troops would carry severe political costs. A March 2026 NPR/PBS News/Marist poll found that 56 per cent of Americans oppose or strongly oppose US military action in Iran,[13] with 86 per cent of Democrats and 61 per cent of independents opposed. Only 36 per cent approve of Trump’s handling of the war. A Reuters analysis noted that voters do not want to repeat the experiences of Iraq and Afghanistan. Casualties could quickly erode support, and both Republican and Democratic lawmakers have criticised the administration for avoiding public debate.

A ground invasion would likely destabilise the region. Iran has shown it can internationalise the conflict; missiles and drones have struck Gulf cities and choked the Strait of Hormuz. A land campaign would almost certainly trigger widespread attacks on US bases, shipping and oil infrastructure, and could draw Russia or China into the fray. It would also strengthen Iranian proxies—Hezbollah, Iraqi militias and the Houthis—opening multiple fronts and jeopardising US relations with Arab partners.

On the humanitarian front, a large‑scale invasion would cause a disaster. Iran’s population of over 90 million would face displacement, economic collapse and likely insurgency. Once troops are deployed, mission creep is inevitable; even limited raids risk expanding into broader commitments. The Arab Center cautions that deposing Iran’s leadership would require occupying Tehran and managing security across diverse regions for years.[14]

Iranian officials have vowed resistance. Foreign Minister Abbas Araghchi told CNN that Iran is “waiting” and ready to confront any ground invasion[15] and sees no need to negotiate or seek a ceasefire. Conversely, White House spokeswoman Caroline Leavitt acknowledged that deploying US ground troops is not part of current plans, while leaving future options open.[16]

Conclusion

The US–Israeli war against Iran is currently an air‑ and sea‑centric campaign aimed at degrading Iran’s missile and naval forces, preventing nuclear proliferation and disrupting proxy networks. Officials in Washington and Jerusalem emphasise that they are not pursuing a full‑scale invasion, and this can be understood by examining the composition of their force deployment in the Middle East compared with their past full-scale invasions of Iraq and Afghanistan. Analyses agree that boots on the ground would be necessary only if objectives expanded to regime change or seizure of nuclear facilities. Such a campaign would require hundreds of thousands of troops, enormous resources and a lengthy occupation, while facing stiff Iranian resistance and severe humanitarian and political costs. With public opinion opposed and regional stakes high, a conventional ground invasion remains unlikely; the value of ‘boots on the ground’ appears confined to targeted raids and defensive operations.

Views expressed are of the author and do not necessarily reflect the views of the Manohar Parrikar IDSA or of the Government of India.

[1] “One Week Into Iran War, The Dangers for the US and Trump Multiply”, Reuters, 7 March 2026.

[2] “Tell Me How This Ends: Six Questions That Will Shape the Outcome of the US-Israeli Operations Against Iran”, Modern War Institute, 4 March 2026.

[3] “One Week Into Iran War, The Dangers for the US and Trump Multiply”, no. 1.

[4] “Tracking the Rapid US Military Build-up Near Iran”, Al Jazeera, 20 February 2026.

[5] “US Positions Amphibious Forces in Indian Ocean Amid Speculation of Ground Operation in Iran”, Daily Excelsior, 31 March 2026.

[6] “2026 Iran Military Strength”, Global Fire Power.

[7] “One Week Into Iran War, The Dangers for the US and Trump Multiply”, no. 1.

[8] “Israel Planning Massive Ground Invasion of Lebanon, Officials Say”, Axios, 13 March 2026.

[9] “One Week Into Iran War, The Dangers for the US and Trump Multiply”, no. 1.

[10] “The US-Israel War on Iran: Analyses and Perspectives”, Arab Center Washington D.C., 2 March 2026.

[11] Ibid.

[12] “Tell Me How This Ends: Six Questions That Will Shape the Outcome of the US-Israeli Operations Against Iran”, no. 2.

[13] “War With Iran, March 2026”, Marist Poll, 6 March 2026.

[14] “The US-Israel War on Iran: Analyses and Perspectives”, no. 10.

[15] “Iran Says It is Ready to Resist Any US Ground Invasion and Sees No Reason for Negotiations”, UNN, 6 March 2026.

[16] “The White House Stated That Deploying American Troops to Iran is Not in the Plans ‘at this moment’”, UNN, 5 March 2026.