The Islamic Republic’s pursuit of nuclear weapons and long-range ballistic missiles is not a bargaining chip. It is an ideological imperative. The theocratic system that has ruled Iran since 1979 treats the acquisition of these capabilities as a religious and revolutionary duty, not a negotiable national interest. U.S. sanctions, diplomacy, and limited strikes have repeatedly demonstrated the same pattern: temporary Iranian setbacks followed by reconstitution. As long as the regime’s core ideology and coercive apparatus remain intact, the nuclear and missile programs will continue. Regime change is therefore not optional theater. It is the only durable way to remove the ideological driver itself.
The Powell Doctrine supplies the proper framework for any serious consideration of force in this case. In earlier writing on the Iran conflict, I have invoked the Powell Doctrine. Some readers misread that doctrine as the simplistic injunction “you break it, you fix it.” That phrase was Colin Powell’s private pre-emptive warning to President George W. Bush about the responsibilities that would follow an invasion of Iraq. The actual Powell Doctrine was something different and more demanding. Forged in the aftermath of Vietnam and applied with clarity during the 1991 Gulf War, it insists that military power be used only when a set of demanding conditions are met—and then used in a manner that produces decisive results rather than prolonged ambiguity. Vital national interests must be engaged; here they are, in the form of a theocratic regime whose ideology treats nuclear weapons and long-range ballistic missiles as non-negotiable instruments of survival and expansion. The political objective must be clear and attainable; in this instance it is the removal of that ideological engine through the enablement of existing Iranian opposition networks, not an American occupation or redesign of Iranian society. Risks and costs must be analyzed with intellectual honesty rather than optimistic assumptions. Non-military instruments—sanctions, diplomacy, and calibrated pressure—must be recognized as having reached the limits of their effectiveness. An explicit exit strategy for ground forces must be designed into the campaign from the outset so that temporary enabling presence does not slide into open-ended entanglement.
And when the decision is made to employ force, that force must be decisive. Colin Powell himself preferred the term “decisive” to the more commonly repeated “overwhelming,” precisely because the goal is successful political-military outcome rather than the indiscriminate application of excess. Decisive force means committing enough combat power—ground, air, and naval—to achieve the defined result quickly, to create irreversible facts on the ground, and to minimize the chance that indigenous partners are left outnumbered, exposed, and ultimately abandoned to a still-coherent adversary. Lesser measures that under-resource the effort invite the very protracted, incomplete campaigns the Doctrine was constructed to prevent. In the Iranian context, that standard requires American ground power sufficient to generate local superiority in the regions where organized opposition actually exists, to protect the rapid expansion of viable liberated space, and to force genuine diversion of regime resources away from its political center—while still remaining far short of the force levels associated with national occupation or nation-building. Anything less fails the Powell Doctrine’s test.
The only organized armed opposition with meaningful capacity is the Kurdish political-military coalition operating from the Kurdistan Region of Iraq (KRI)—the same Kurds who assisted us with Operation Iraqi Freedom—into northwestern Iran. Even under optimistic assessments, estimates place its combined strength in the mid-teens to low twenties of thousands of fighters, concentrated in the Zagros border region. These forces are experienced in guerrilla and light-infantry operations but lack the mass, heavy weapons, and protected space required to hold significant territory against a determined counterattack. Other opposition networks—Baloch in the southeast, Arab communities in Khuzestan, and fragmented Persian protest movements—possess grievances and intermittent capacity but not comparable organized combat power. Relying on these Kurdish forces as the vanguard carries a significant political risk that is central rather than peripheral: the IRGC will immediately frame the effort as an American-backed separatist plot to balkanize Iran, and Persian nationalism remains deeply entrenched. Many Iranians who despise the theocracy may still rally to the regime’s side if they perceive the country’s territorial integrity under threat. A liberated Kurdish zone expanding under American protection can easily become the regime’s most effective mobilization tool. Information and political lines of effort must therefore be treated as co-equal with the military main effort from the outset—explicitly framing the campaign as the removal of a theocratic regime rather than any challenge to Iranian territorial integrity, elevating Persian and multi-ethnic opposition voices, and making unmistakably clear that American support ends the moment the regime’s coercive monopoly is broken.
Arrayed against the Kurds are the regime’s loyal forces. The Islamic Revolutionary Guard Corps Ground Forces number roughly 150,000–190,000 and are organized into provincial commands optimized for internal control. The regular army adds another 350,000. The Basij paramilitary network can mobilize hundreds of thousands more for repression and local defense. The regime’s true center of gravity is not the periphery. It is the cohesion of the IRGC and Basij in Tehran and the major urban centers, the integrity of the command structure, and the ability to allocate internal security resources without losing the political heartland. Peripheral losses impose costs. They do not automatically collapse the center of gravity unless they stretch those resources past the breaking point and trigger cascading defections.
A purely advisory or minimal-footprint approach leaves the Kurdish forces vulnerable to the very IRGC reinforcements already observed moving toward the border. That is the definition of an under-resourced campaign. Decisive force relative to this balance requires American ground combat power sufficient to create local superiority in the primary resistance theater, protect rapid expansion of a viable liberated zone, and open a secondary axis that forces genuine diversion of regime attention and mobile reserves.
The enabling task force should peak at 25,000–35,000 American ground personnel. Special Operations Forces form the advisory core—approximately 2,500–3,500 operators sized for intensive combat advising at the density historical campaigns show produces results. Conventional forces supply the decisive local combat power: a reinforced airborne or light infantry brigade package paired with a mobile or Stryker equivalent focused on the northwest, and two Marine Expeditionary Units or equivalent amphibious forces oriented on the southern Gulf littoral and economic nodes. This total number represents an operational sweet spot rather than an under-resourced compromise: it is large enough to achieve mass, overmatch local IRGC provincial commands, and protect partner assembly areas, yet strictly bounded to prevent the mission creep and administrative footprint that turn an enabling action into an occupation.
These ground formations require robust, theater-wide air and missile defense. Crucially, a prerequisite for inserting forces into sovereign Iranian territory is the advance reinforcement of Integrated Air and Missile Defense (IAMD) systems across CENTCOM host nations. Hardening U.S. and allied staging hubs in Qatar, Bahrain, Kuwait, and the UAE against Iranian ballistic missile, cruise missile, and drone saturation attacks is an essential enabling condition before offensive operations begin. Staging and sustainment through the Kurdistan Region of Iraq will face immediate pushback: Baghdad, under heavy Iranian influence, can be expected to resist, while Turkey regards any armed autonomous Kurdish zone on its borders as an existential concern and may actively complicate logistical lines and airspace access. These political realities make intensive, continuous diplomatic engagement with both Baghdad and Ankara a critical enabling requirement—not a secondary or parallel task. This engagement cannot merely be a request; it must be a transactional demand. Washington must leverage its defense apparatus, military sales, and NATO frameworks to secure ironclad deconfliction agreements, guaranteeing that Ankara will not strike the very proxy forces American operators are actively advising on the ground. Because a total diplomatic veto by Ankara or Baghdad would paralyze northern operations, military planning must treat diplomatic engagement as necessary but insufficient. The campaign design must incorporate secondary, non-KRI logistics lines—including direct over-the-shore logistics and aerial insertion via the southern littoral—to ensure the operational concept does not collapse if regional neighbors chokepoint northern access.
This is not an invasion force. It is a geographically limited package designed solely to generate decisive local force ratios in the specific regions where indigenous capacity already exists. Air and naval power remain the primary source of lethality—persistent ISR, close air support, interdiction of regime reinforcements, and continued degradation of residual missile and air-defense infrastructure. The ground component exists only to convert that airpower advantage into irreversible territorial and political gains that indigenous forces can then hold.
The main effort is the rapid establishment and expansion of a contiguous, defensible zone in Iranian Kurdistan. Special Forces advisors embed with Kurdish formations while conventional forces supply the mobility, fires, and protection needed to hold against IRGC counterattacks. The objective is a liberated space large enough to attract additional fighters and defectors, and durable enough that the regime cannot simply reoccupy it once American advisors rotate out.
The secondary effort is high-impact southern denial. Amphibious and joint forces seize and temporarily hold selected Gulf islands and export nodes such as Kharg Island to deny the regime revenue, complicate its maritime posture, and force it to divert resources from the northwest. This is a high-visibility, high-escalation action with immediate oil-market, regional, and great-power consequences; its duration of hold, rules of engagement against Iranian naval and missile response, and political signaling must be tightly defined in advance rather than treated as a supporting raid. Information operations run in parallel, amplifying protest activity and encouraging defections without American forces assuming responsibility for urban security in the Persian heartland.
The campaign is sequenced for speed. Initial forcible establishment of protected zones occurs under heavy air cover within the first 60 days. Expansion and partner force maturation follow over the subsequent 90 days. By the five-to-nine-month mark, indigenous forces—now operating from expanded and better-supplied positions—should be capable of holding the key gains with residual American air and naval support. This timeline is ambitious; the fog of war, IRGC artillery and residual ballistic-missile fire, and the inevitable political pressure to either reinforce or withdraw once American forces begin taking casualties could easily influence the ground presence. The campaign design offsets these residual threats through persistent air and naval interdiction, continuous degradation of missile and air-defense systems, and the ground component’s ability to create protected space faster than the regime can mass effective counterattacks. Even with those offsets, the risk of mission creep remains real, which is why the Powell Doctrine’s insistence on explicit exit criteria and refusal of nation-building responsibilities is the only reliable safeguard against that escalation dynamic. Once predefined conditions are met, the bulk of conventional ground forces and most Special Operations advisors begin phased withdrawal. A small residual advisory presence and over-the-horizon reach remain available if required. The exit criteria are explicit: indigenous forces able to sustain operations under U.S. air and naval overwatch, measurable erosion of regime control in multiple peripheral regions, and no continuing requirement for American ground combat troops to prevent immediate reversal of gains.
At the conclusion of the decisive phase, the theocratic regime no longer exercises coherent control over the northwest. A substantial liberated zone exists under indigenous Kurdish-led administration, with local security provided by expanded opposition forces rather than American units. Southern economic and maritime nodes remain under temporary denial or contested control long enough to have inflicted lasting revenue and prestige damage. Regime command-and-control in the periphery is fragmented. IRGC and Basij units have been forced into repeated, costly attempts to reinforce multiple axes simultaneously, exposing the limits of their internal cohesion.
The center of gravity—Tehran and the major urban population centers—has not been occupied by American forces. It has, however, been placed under sustained political and psychological pressure. The ideology that treats nuclear weapons and ballistic missiles as sacred obligations has lost its protected sanctuary. Leadership attrition, resource diversion, and visible loss of territorial control create the conditions for further fracture, elite defections, or a broader popular challenge that Iranians themselves must prosecute. These conditions are plausible; they are not automatic. The IRGC and Basij have repeatedly shown the ability to absorb peripheral pain while retaining urban control. Clearer observable indicators—measurable breakdowns in command cohesion, sustained elite defections, or irreversible loss of internal security capacity in the heartland—would be required to distinguish genuine cracking of the center from mere stress. What replaces the theocracy is not an American-designed government. It is whatever political arrangements Iranians, including the opposition networks that bore the fighting, are able to negotiate or impose. Federal arrangements, regional autonomy, or a more centralized successor state are all possible. None of them are American responsibilities.
The nuclear and missile programs lose their institutional protector. Facilities and expertise may still exist, but the regime that treated their pursuit as non-negotiable no longer holds the monopoly on force required to continue them without interruption. Residual American air and naval power, combined with international monitoring, can address any reconstitution attempts without reintroducing ground combat forces.
American casualties under a decisive enabling campaign are much higher than pure standoff options but far lower than a full-scale invasion. Optimistic estimates fall in the low hundreds killed; pessimistic cases that encounter heavier regime counter-concentration could reach the mid-to-high hundreds or low thousands. The primary sources of loss occur through residual missile and drone attacks on temporary U.S. nodes and staging areas, exposure during combat advising, and limited conventional engagements on the periphery. As a combat veteran myself, I do not take projected loss of life lightly—but I do know those who serve do so knowing the risk involved and only ask that sacrifices not be made in vain. These risks are accepted because the alternative carries higher long-term strategic cost. Crucially, fulfilling the Powell Doctrine also requires securing explicit domestic legitimacy before troops cross the line of departure. The American public is understandably hostile to new Middle Eastern deployments in a post-Afghanistan era, and any administration proposing this force package will face fierce domestic headwinds. Political leadership must formally seek a targeted Authorization for Use of Military Force (AUMF) from Congress, build transparent public support prior to insertion, and plainly articulate the strategic reality: the choice is not between this campaign and peace, but between accepting a limited, decisive ground commitment today or fighting a catastrophically costlier war against a nuclear-armed Iranian state tomorrow.
The principal risks remain incomplete political translation and partner limitations. Military success on the periphery does not automatically produce the rapid collapse of theocratic control in Tehran. The opposition is fragmented, the regime retains significant residual capacity for urban repression, and no unified national alternative currently exists. The result could be a messy, prolonged transition. Those outcomes are still preferable to an intact ideological regime free to reconstitute its nuclear and missile programs. Critics will invoke post-Gaddafi Libya or civil-war Syria. Residual IRGC networks, technical nuclear expertise, and materials will not vanish, and radicalized fragments may seek external sponsors. Yet a fractured Iran lacks the unified state apparatus and defense industrial base required to sustain a centralized nuclear weapons program or project terrorism at the scale the theocracy has achieved. Those residual risks are real and will require over-the-horizon management; but they remain more containable than a coherent, nuclear-armed theocracy. Critically, these outcomes—however messy—remain Iranian problems that Americans do not have to manage or underwrite on the ground.
Critics will argue that any ground commitment risks mission creep into nation-building. The Powell Doctrine’s exit criteria and the explicit refusal to assume responsibility for Iranian governance are the safeguards. Others will claim that air and naval power alone can achieve the same result. Experience and history show otherwise: pressure without a credible ground component has repeatedly allowed the regime to absorb costs and reconstitute. Still others will demand larger force packages for higher certainty. That path leads toward an occupation the United States should reject.
The recommended package occupies the narrow space the Powell Doctrine requires: decisive relative to the actual balance of forces and the limited objective, limited relative to the scale of the country and the refusal to nation-build. It removes the ideological engine of the nuclear and missile threat by enabling Iranians who already oppose the regime to impose costs the theocracy cannot indefinitely sustain. When the ground forces leave, they leave behind a weakened, territorially compromised, and politically fractured system whose residual capabilities can be managed from the air and sea. The rest is for Iranians to decide. That is both strategically sufficient and consistent with American interests.
Stephen D. Cook is a retired U.S. Army Special Forces Lieutenant Colonel with 25 years of service. A combat veteran decorated for both heroism and valor, he is the author of the field manuals When We’re Finished and Choose the Heavier Ruck, and the techno-thriller precision-strike trilogy leading with In the Shadows of the Sky. His work explores the intersection of elite military decision-making, intuition, and disruptive leadership. He is based in St. Augustine, Florida.
