Ground Forces in Iran—for What?
Success is impossible if there’s no goal in the first place.
PRESIDENT TRUMP IS APPARENTLY considering sending American ground combat forces into Iran. Infantry and amphibious forces have been flowing to the region for weeks—first Marine expeditionary units, then elements of the 82nd Airborne Division, and now rumors of tens of thousands of additional troops. The U.S. military has been war-gaming an Iranian conflict for decades—but that doesn’t mean the United States is ready to execute.
In 1988, as a major at Fort Leavenworth, I sat in a classroom war-gaming a conflict with Iran. All the officers in the course were assigned positions on different teams, from commanders and their staffs to politicians and policymakers. We were required to make decisions—about objectives, force size, sequencing, and risk—and then watch those decisions play out in a simulation against a thinking enemy.
What made the experience particularly valuable was not just the various scenarios, but the composition of those in the room. Alongside Army officers were young officers of equivalent rank from other services: Air Force planners, Navy surface warfare officers, military intelligence professionals, and Special Forces soldiers. Each saw the problem from a different perspective. Air Force representatives focused on shaping the battlefield before ground forces moved. Naval officers thought in terms of sea control, chokepoints, and resupply. The intelligence officers challenged every assumption embedded in our plans. The Green Berets emphasized what could (and couldn’t) be done before conventional forces were ever committed.
What we learned—sometimes the hard way—was that Iran is a complex environment, and no military action stands alone. Tactical moves must be sequenced into an operational campaign, and military campaigns must be tied to a political objective. Many of the officers in that classroom would go on to help plan Desert Storm, one of the most successful large-scale military campaigns in modern history, precisely because those connections between ends, ways, and means were made clear to all of us.
Today, the same basic questions we wrestled with in that classroom are emerging in the real world. What is the objective? What is the end state? And how much military force does it take to achieve it? In war, you do not start with forces; you start with what you are trying to accomplish. Only then do you determine what kind of force is required. Right now, that clarity is missing.
No serious planner believes the United States is preparing to seize and control all of Iran. That would require a force far larger than anything currently being discussed. Iran is three times the size of Iraq, with more than double its population, more complex terrain, and a regime that has spent decades preparing for asymmetric resistance. Even the most limited comparison to Iraq should give pause: The United States deployed hundreds of thousands of troops there and still struggled to translate battlefield success into lasting strategic outcomes.
So, if not regime control, then what?
What appears to be emerging is a menu of limited-objective options: seizing a key piece of terrain like Kharg Island, isolating parts of the Strait of Hormuz, conducting raids, escorting ships, or recovering sensitive nuclear material. Each of these missions, by itself, could be militarily feasible. But none of them, on its own, constitutes a strategy. They only make sense if they are tied to a clearly defined political end state.
Elements of the 82nd Airborne and forward-deployed Marine units are not designed to fight and sustain a long campaign. They are what are often called “in extremis forces”—units built to respond rapidly to emergencies, to deploy on short notice, seize key but limited objectives, and hold on just long enough until heavier forces arrive to enter the fight. They are exceptionally capable, but they are the first wave, not the force that finishes a war.
That distinction matters. Because what is being assembled looks very much like what might be called the “baby bear” option. It is not the “too big” force of a full-scale invasion, nor the “just right” force aligned to a clearly defined campaign. It is something smaller—more limited, more politically palatable, and easier to initiate. But it is also likely insufficient for anything beyond the narrowest objectives.
It’s difficult to figure out what size a force is needed for a particular operation. History tells us that when force size is miscalculated on the low side—when objectives are larger or more complex than initially understood—the results are almost always disastrous. Missions expand. Risks multiply. Reinforcements are required. What begins as a limited operation becomes something far more demanding, often under conditions far less favorable than at the outset. Think the 2003 American-led coalition in Iraq before the surge of 2007, or the Russians in Ukraine in 2022.
This is where the troop-to-task principle becomes critical. Assigning the right number and type of forces to accomplish a mission does not end with the initial assault. The troop-to-task analysis changes as operations progress and different forces are required to hold ground, reinforce, sustain operations, defend against counterattack, and ultimately achieve the desired political effect. Calculating those numbers based on anticipated actions or setbacks are critical when preparing for any insertion of entry-level forces.
Consider a potential operation against Kharg Island, the hub through which the vast majority of Iran’s oil exports flow and median explicit target of Trump’s threats. A force like a brigade from the 82nd Airborne or a Marine expeditionary unit could likely seize the island. But seizing terrain is only the beginning. Holding it against Iranian missile strikes, drone attacks, naval mines, IEDs, and counterattacks from the mainland is a far more complex challenge. It requires air and missile defense, logistics pipelines, intelligence support, engineering assets, medical capability, and sustained reinforcement. And it requires a clear understanding of why the island was seized in the first place—what effect is being sought, and for how long.
When the lens is widened to the Strait of Hormuz itself, the problem becomes even more complex. If the objective is to protect maritime traffic through one of the world’s most critical chokepoints, then Kharg is arguably an unwelcome distraction. The geography of the strait places enormous importance on a small cluster of islands that Iran uses to monitor and potentially control shipping lanes—Abu Musa, Greater Tunb, and Lesser Tunb. Each of these islands sits astride key maritime routes. Each has been fortified. And each would represent its own tactical objective, requiring separate planning, separate assaults, and separate sustainment.
Seizing and controlling one island would be a battle. Ensuring the uninterrupted flow of global commerce through a contested waterway by securing several of these islands begins to look like a campaign. And controlling the entire area while under constant threat from missiles, drones, mines, and fast-attack craft would require a level of force and sustainment far beyond what “limited” options imply. This is how complexity multiplies in war. What appears at first to be a discrete task quickly becomes a network of interdependent operations, each adding requirements and risk.
Even then, if mission success meant protecting the Strait of Hormuz to the satisfaction of shipping companies and insurers to ensure the flow of dry and wet cargo through that narrow passageway, even controlling these three islands might not be enough for success. A military force would also be required to secure much of the Iranian coast as well, while continuing to degrade their missile capability while countering the mature Iranian drone threat.
The same dynamic applies to the most ambitious option being discussed: a mission to seize Iran’s stockpile of highly enriched uranium. On paper, it might be described as a raid—insert special operations forces, secure the material, and extract. The reality would be far more complex. Such a mission would require precise intelligence—knowing not just where the material is, but whether it has been moved, dispersed, or concealed. It would require specialized units capable of breaching hardened facilities, identifying and handling some 800 lbs. of radioactive material, and securing the site under combat conditions. It would require air superiority, rapid extraction capability, and contingency planning for everything from booby traps to deception operations.
Even then, the risks remain enormous because current intelligence is likely incomplete. The material may not be where it’s expected. The site may be defended. A small raiding force could find itself isolated under fire, facing rapid Iranian counteraction. And the political consequences of U.S. forces operating inside a nuclear-related facility would be immediate and profound. This is not a simple raid. It’s a high-risk operation with strategic consequences far beyond its tactical scope—and exactly the kind of “limited” mission that can pull a nation into a much longer and more strategically damaging war.
All of this points to a deeper issue: the gap between tactical possibility and strategic clarity. Almost every option being discussed is feasible in isolation. The U.S. military can seize terrain, conduct raids, interdict shipping, and project power with unmatched precision. But war is not a collection of isolated actions. It’s organized violence and controlled chaos in pursuit of a political objective. Campaigns require coherence—alignment between ends, ways, and means, and an understanding that the enemy will react.
Right now, that alignment is not evident.
What is the end state? Is it to reopen the Strait of Hormuz? To degrade Iranian capabilities? To force negotiations? To destabilize the regime? To capture and abscond with nuclear material? Each of those objectives would require a different level of commitment, a different force structure, and a different tolerance for escalation. Without clear answers to those questions, even successful operations risk becoming disconnected from meaningful outcomes.
Introducing American ground forces into Iran—even in limited numbers—is not a symbolic act. It’s a decision that sets events in motion. If the force is too small for the objective, it will require reinforcement. If the objective is unclear, success will be temporary. And if the end state is undefined, the war and the enemy will define it for us.
Once American troops are committed, the cost is no longer measured in plans or projections. The solution isn’t another briefing slide or another two-minute sizzle reel of explosions. The cost of correcting a mistake is measured in time, in escalation, and ultimately in American lives. Young men and women will be asked to carry out extremely difficult missions in a complex and unforgiving environment against an enemy that has prepared for decades and sees our invasion as an existential threat.
Before we take that step, we owe our military and our citizens more than a “baby bear” plan that is easy to start and hard to finish. We owe them a strategy worthy of the risk we ask of them.