Inside the Pentagon's Plan for Weeks of Ground Operations in Iran — and the Risks That Come With It

Five weeks into a U.S.-Israeli military campaign against Iran that began with the February 28 joint strikes that killed Ayatollah Ali Khamenei and other senior leaders [1], the Pentagon is now preparing options for something far more consequential: extended ground operations on Iranian soil [2]. The plans under consideration range from an amphibious seizure of Kharg Island — Iran's primary oil export terminal — to special operations raids deep inside the country aimed at securing highly enriched uranium buried within hardened nuclear facilities [3].

Whether President Donald Trump will approve any of these plans remains an open question. "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," White House Press Secretary Karoline Leavitt said on March 29 [1]. But with roughly 3,500 additional troops arriving aboard the USS Tripoli on March 27, joining thousands of Marines and 82nd Airborne paratroopers already flowing into the theater, the military is clearly positioning for something beyond the air campaign that has defined the conflict so far [2][4].

The Force Buildup: Scale and Composition

The current U.S. force posture in the Middle East has roughly doubled since January. Before the war began, approximately 35,000 American troops were stationed across the region. That number has climbed steadily: the Pentagon is weighing a plan to deploy up to 10,000 additional ground troops, on top of the roughly 5,000 Marines and 2,000 Fort Bragg-based paratroopers already headed to the region [4][5].

Source: Pentagon / Military Times

Data as of Mar 29, 2026CSV

The 31st Marine Expeditionary Unit, deployed with transport and strike fighter aircraft as well as amphibious assault vehicles, forms the core of the newly arrived force [1]. The composition — heavy on light infantry, Marines, and special operations units — tells its own story about the kind of operations being contemplated: quick seizures and raids, not sustained armored offensives.

For comparison, the 2003 invasion of Iraq began with approximately 130,000 U.S. troops crossing the Kuwaiti border, supported by 1,700 aircraft and a massive naval armada [6]. The 2001 invasion of Afghanistan started with a far lighter footprint of roughly 1,300 special operations forces, supplemented by CIA paramilitary teams and extensive air power, growing to about 10,000 conventional troops within weeks [6]. The current Iran buildup falls between these models — larger than the initial Afghan insertion but far smaller than the Iraq force — reflecting what officials describe as a "weeks, not months" timeline [2].

Two Operations, Two Sets of Risks

Pentagon planners have outlined at least two distinct categories of ground operations [3].

The first centers on Kharg Island, a strategically vital hub through which roughly 90 percent of Iran's oil exports flow. Seizing the island would choke off Tehran's primary revenue source and is, according to retired Gen. Frank McKenzie, former U.S. Central Command commander, "part of a longstanding plan" [7]. Retired Lt. Gen. Karen Gibson, former CENTCOM intelligence director, described an amphibious operation against the island as "exactly the kind of mission that the Marine Corps was designed to do" [7].

But Kharg Island sits just 12 miles from the Iranian mainland. Retired Gen. Joseph Votel, another former CENTCOM commander, warned that forces stationed there "could risk drone or missile assaults if they're not able to get into protected locations or have their own defensive capabilities" [7].

The second category is far more ambitious: sending forces deep into Iran's interior to locate and secure enriched uranium at hardened nuclear facilities. This is the operation that has drawn the sharpest warnings from retired military leaders. "They would get swallowed up pretty quickly if they went into the mainland," Votel said, noting that the current force lacks the armored vehicles and tanks needed for sustained ground offensives [7]. Securing even one nuclear site would require "hundreds of troops per location with engineering support," according to military analysts, and would expose supply chains for food, water, and ammunition to constant interdiction [7].

The Legal Question: Who Authorized This?

The administration has not invoked any existing Authorization for Use of Military Force to justify the Iran campaign. The 2002 Iraq AUMF was repealed last year, and the 2001 AUMF targeting al-Qaeda has no credible connection to Iran [8][9]. Instead, in a March 2 war powers report, the White House stated explicitly that the president acted "pursuant to his constitutional authority as Commander in Chief" under Article II [9].

The administration applies a two-part test: first, that military action serves "sufficiently important national interests" — a standard that legal scholars describe as "extraordinarily deferential" — and second, that the "nature, scope, and duration" do not constitute a war requiring congressional approval [9]. Under this framework, the White House argues that Iran's nuclear and ballistic missile programs meet the national interest threshold, and that operations remain sufficiently "limited" to fall within presidential authority [9].

Constitutional law scholars have pushed back hard. The Lawfare analysis notes that the administration's narrow focus on risk to U.S. military personnel "abandons the Framers' intent for congressional war authority as a check on overseas adventurism" [9]. Earlier executive branch legal opinions incorporated a broader assessment of casualties, the defensive nature of operations, and other factors — not simply whether American troops faced direct fire [9].

Congress has tried, and failed, to assert itself. On March 4, the Senate rejected a War Powers Resolution by a 47-53 vote that would have forced Trump to seek congressional consent. A similar resolution failed in the House the following day [8]. Under the 1973 War Powers Resolution, the president must terminate military operations within 60 days (extendable to 90) without congressional authorization — a clock that is now ticking [9].

Trump himself has muddied the legal waters. As reported by Truthout, the president acknowledged avoiding the word "war" in reference to the campaign specifically to sidestep congressional accountability requirements [10].

The Nuclear Targets and What Strikes Have Achieved

The ground operations under discussion exist against the backdrop of months of air strikes aimed at Iran's nuclear infrastructure. Operation Midnight Hammer, launched on June 22, 2025, sent seven B-2 Spirit bombers from Whiteman Air Force Base on an 18-hour flight to strike three nuclear facilities — Fordow, Natanz, and the Isfahan Nuclear Technology Center — with GBU-57A/B Massive Ordnance Penetrator bunker-buster bombs and Tomahawk missiles [11][12].

The results were mixed. A U.S. assessment found that only one of the three sites — the Fordow Uranium Enrichment Plant, buried 80-110 meters underground near Qom — was "mostly destroyed," setting enrichment work back by what officials estimated as "as much as two years" [12][13]. The other two facilities, Natanz and Isfahan, sustained less damage and could resume enrichment "in the next several months" [12]. A follow-up strike on Natanz on March 21, 2026, using additional bunker-buster ordnance, prompted Russia to condemn the attack as "a blatant violation of international law" and the IAEA to urge restraint "to avoid any risk of a nuclear accident" [11].

The estimated two-year setback to the overall program is roughly comparable to what the 2010 Stuxnet cyberattack achieved — which destroyed approximately 1,000 centrifuges at Natanz — but with far greater collateral consequences [14]. And nonproliferation experts stress a fundamental asymmetry: strikes can destroy facilities but cannot erase knowledge. As one War on the Rocks analysis put it, "A government with that history is unlikely to collapse quickly because of military strikes. It is more likely to adapt. And if it adapts, the nuclear program may adapt with it — moving further into concealment, dispersal, and gradual reconstitution" [15].

Before the strikes, General Michael Kurilla, then-CENTCOM commander, assessed that Iran's "current stockpiles and available centrifuges are sufficient to produce its first 25 kg of weapons-grade material in roughly one week and enough for up to ten nuclear weapons in three weeks" [13]. The IAEA has since reported it has "lost continuity of knowledge" over Iran's stockpile of 440 kg of uranium enriched to 60 percent purity — meaning the international community cannot fully account for the material that existed before the strikes [13].

Civilian Toll and Humanitarian Impact

The war has already exacted a heavy price on Iranian civilians. Iran's health ministry reports that between February 28 and March 25, 1,500 people were killed and 18,551 injured [16]. The human rights organization HRANA, tracking casualties independently, documented 3,114 deaths by March 17, including 1,354 civilians [16].

One strike on a school in Minab killed more than 175 people, mostly children — described as the largest number of child casualties in a single U.S. military attack since the My Lai massacre in Vietnam [16]. Over 3.2 million Iranians are now internally displaced, primarily from major urban centers [16][17]. The Norwegian Refugee Council reports that casualties and infrastructure damage have been recorded across at least 20 provinces, with the Iranian government stating that more than 81,000 civilian structures have been damaged, including 275 medical facilities [17].

UN High Commissioner for Human Rights Volker Türk issued a statement that "civilians bear the brunt of reckless war in the Middle East" [18]. Amnesty International has called for protection of civilians and respect for international humanitarian law, specifically citing proportionality obligations under the Geneva Conventions [19].

Specific population data for the areas surrounding Fordow and Natanz is limited in open-source reporting. Fordow is located near the city of Qom (population approximately 1.3 million), while Natanz is a smaller city in Isfahan province. International humanitarian law requires that attacking forces take "constant care" to spare civilians and that expected civilian harm not be "excessive in relation to the concrete and direct military advantage anticipated" — a proportionality calculation that grows more demanding as population density increases [19].

The Cost: $891 Million Per Day and Climbing

The financial scale of the Iran campaign dwarfs recent U.S. military operations. The Center for Strategic and International Studies estimates that the first 100 hours of Operation Epic Fury cost $3.7 billion — approximately $891 million per day [20]. Of that, only $178 million fell within existing budget allocations. The remaining $3.5 billion was entirely unbudgeted [20].

Source: CSIS / CBO estimates

Data as of Mar 29, 2026CSV

The cost breakdown reveals where the money goes: $1.5 billion in offensive strike munitions expended, $1.7 billion in air defense interceptors used against Iranian retaliation (defending against 500 ballistic missiles and 2,000 drones), and $309 million in equipment losses including three F-15EX aircraft at $103 million each [20]. The Pentagon burned through $5.6 billion worth of munitions in just the first two days [21].

For context, Iraq War operations during the 2003 invasion cost an estimated $350 million per day in inflation-adjusted terms, and Afghanistan at peak surge cost roughly $300 million per day [20]. The Iran campaign is running at more than double the daily rate of either.

The Pentagon has asked the White House to approve a supplemental budget request exceeding $200 billion to fund the war [21]. Defense Secretary Pete Hegseth told reporters, "Takes money to kill bad guys," when asked about the figure [22]. Possible funding mechanisms include a supplemental appropriation — the approach used for Iraq and Afghanistan — or allocation from existing Department of Defense reconciliation funds totaling $150 billion [20].

Oil Markets and Economic Spillover

The conflict has sent energy markets into upheaval. WTI crude oil prices have surged from approximately $59 per barrel in late December 2025 to $98.71 at the March 2026 peak — a year-over-year increase of 28.6 percent [23]. The seizure of Kharg Island, if it proceeds, would remove a significant share of Iran's roughly 1.5 million barrels per day of exports from global markets, with further price implications.

Source: FRED / EIA

Data as of Mar 23, 2026CSV

Regional Reactions: A Fractured Coalition

The war has produced unusual regional dynamics. For the first time in history, Iran struck all six Gulf Cooperation Council countries — Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the UAE — killing soldiers and civilians across the region [24]. This shifted Gulf state postures from cautious neutrality to condemnation of Iran, though not necessarily endorsement of the U.S. campaign.

NATO allies have been drawn in partly involuntarily: Iranian attacks damaged an Italian military installation in Iraq and Kuwait and a French naval facility in the UAE [24]. NATO forces shot down Iranian drones and missiles near Incirlik Air Base in Turkey [24]. But on March 17, Trump posted on Truth Social renouncing NATO's assistance and criticizing allies in the Indo-Pacific — Japan, South Korea, and Australia — for refusing to join U.S.-led attacks [24].

Bloomberg reported on March 27 that the administration was signaling to allies that it had "no immediate plans for a ground invasion" [25] — a message seemingly at odds with the simultaneous troop buildup and operational planning reported by the Washington Post and others.

The Case Against: What Opponents Inside the Military Say

The strongest opposition to ground operations comes from within the U.S. military establishment itself. Retired Gen. Votel warned against "conflating tactical successes with strategic policy success" [7]. His concern — shared by multiple former CENTCOM commanders — is that seizing a piece of territory or destroying a facility produces a tangible but fleeting result, while the strategic consequences multiply.

Iran has already demonstrated the capacity to activate proxy networks across the region. Hezbollah launched rockets and drones against northern Israel on March 2, drawing Lebanon back into conflict [26]. Pro-Iranian Iraqi militias claimed responsibility for drone attacks on U.S. troops at Baghdad airport and a base in Erbil, and have bombarded the U.S. Embassy compound in Baghdad for weeks [26][27]. Houthi leaders told the Associated Press they intended to resume missile and drone attacks on Red Sea shipping [26].

A Georgetown Journal of International Affairs analysis titled "Tell Me How This Ends" framed the core strategic dilemma: ground operations risk widening the war into Iraq, Syria, Lebanon, and Yemen simultaneously, each theater posing distinct threats to American forces and regional stability [28]. Seven U.S. troops had been killed in Iranian attacks and more than 300 wounded as of late March — figures that military planners expect would rise significantly with ground operations [7].

The Stimson Center's post-Khamenei analysis noted that the elimination of Iran's supreme leader has not neutralized the proxy network but may have loosened central control, making the behavior of groups like Hezbollah and Iraqi militias less predictable [29]. Foreign Policy reported that Iran's proxies are currently "out for themselves," constrained more by domestic politics and diminished capabilities than by any coordinated stand-down [26].

The Nonproliferation Paradox

Even if ground operations succeed on their own terms — securing enriched material, further degrading nuclear infrastructure — the long-term nonproliferation picture remains uncertain. The estimated two-year setback from combined air strikes is roughly equivalent to what Stuxnet achieved through cyberattack in 2010 [12][14]. But Iran has since dispersed key personnel, mastered enrichment technology at multiple levels, and — according to the IAEA — accumulated stockpiles whose current status is unknown [13][15].

The Carnegie Endowment for International Peace has argued that "coercive approaches to weapons of mass destruction in the Middle East have not produced more manageable nonproliferation outcomes" [30]. Military strikes can destroy centrifuges but cannot destroy the knowledge of how to build them. And as the War on the Rocks analysis concluded, the Iranian program is likely to "adapt — moving further into concealment, dispersal, and gradual reconstitution" rather than disappear [15].

The fundamental question facing the administration is whether weeks of ground operations — with their attendant risks in casualties, cost, regional escalation, and international law — can achieve something that months of air strikes and a decade-old cyberattack could not: a durable end to Iran's nuclear ambitions. The historical record, and the weight of expert analysis, suggests the answer is more complicated than any military plan can resolve.