There is a particular audacity to naming a foreign policy doctrine after an intellectual tradition you are simultaneously dismantling. The Trump administration’s “flexible realism,” as it has been branded in both the 2025 National Security Strategy and the 2026 National Defense Strategy, presents itself as the mature, unsentimental successor to liberal internationalism — a philosophy finally willing to look the world in the eye and see it as it is: governed, as White House adviser Stephen Miller put it to CNN, “by strength, by force, by power.” But as Operation Epic Fury grinds into its fourth week, as Brent crude trades above $110 a barrel, as the Strait of Hormuz — through which roughly 20 percent of the world’s seaborne oil flows — is functionally closed for the first time in history, and as the International Energy Agency has characterized the disruption as “the greatest global energy and food security challenge in history,” a more uncomfortable question presses itself onto policymakers and investors alike: Is “flexible realism” an actual strategy, or is it a retroactive label applied to whatever the president decided to do that week?
The distinction matters enormously. And the Iran war, more than any other event of the Trump second term, tears the label off the box.
What “Flexible Realism” Claims to Be
To understand the failure, you first have to take the doctrine seriously on its own terms. The 2025 National Security Strategy and the subsequent 2026 National Defense Strategy are not throwaway documents. They represent a genuine attempt — by serious people, including Under Secretary of Defense for Policy Elbridge Colby — to articulate a coherent departure from post-Cold War liberal internationalism. The core premise is reasonable enough: the United States has overextended itself chasing liberal-order management projects — from Kabul to Kiev — while China has systematically converted its growing economic weight into military and diplomatic leverage. A reorientation toward hard power, prioritized interest, and unsentimental coercion is, in this telling, not a retreat from grand strategy but an embrace of it.
“Flexible realism,” as the NDS frames it, is supposed to offer the best of classical realism — the acceptance of power politics as the currency of international relations — without the rigid constraints that orthodox realists like Stephen Walt at Harvard or John Mearsheimer at Chicago have traditionally imposed: respect for sovereignty, skepticism of regime change, prioritization of great-power stability over third-world adventurism. It is, in other words, realism with an asterisk. Or, more precisely, realism with a Twitter account and a Truth Social post.
The problem, as Rebecca Lissner of the Council on Foreign Relations and Mira Rapp-Hooper of the Brookings Institution argue in a landmark essay published this week in Foreign Affairs — titled, pointedly, “The False Promise of Flexible Realism” — is that the doctrine collapses the moment it confronts an actual strategic choice that requires discipline, sacrifice, or deferral of domestic political gain.
Iran: Where the Doctrine Meets Reality — and Shatters
The architecture of the Iran conflict reveals three consecutive failures of “flexible realist” logic, each one more damaging than the last.
First: the strategic sequencing failure. Classical realism — the Kissinger variety, the kind that produced the opening to China or the détente architecture — operates on a principle of economy of force: you do not open a second-order theater while a first-order strategic competition remains unresolved. Every serious defense analyst in Washington agrees, and the 2026 NDS itself asserts, that China is the “pacing threat” and the central organizing challenge of American grand strategy. Flexible realism, properly applied, would therefore demand extreme caution about any military operation that consumes carrier strike groups, drains precision-munitions stockpiles, elevates oil prices globally, and hands Beijing a strategic windfall — all of which Operation Epic Fury has done simultaneously. The deployment of both the USS Abraham Lincoln and USS Gerald R. Ford carrier strike groups to the Persian Gulf represents an extraordinary commitment of the Navy’s finite carrier capacity to a theater that, by the administration’s own strategic logic, ranks below the Indo-Pacific in priority.
Second: the nuclear logic failure. Operation Midnight Hammer in June 2025 struck Iran’s declared nuclear facilities at Fordow, Natanz, and Isfahan with bunker-buster munitions. The Centre for Strategic and International Studies notes that, even after that campaign, “Iran still possesses 400 kilograms of 60 percent enriched uranium, and the exact location of that nuclear material remains unknown.” You cannot bomb a country’s nuclear desire — only its current infrastructure. As LSE analysts have warned, the strikes may have transformed Iran “from a state with latent nuclear capability into one with a nuclear grievance” — a historically reliable precursor to accelerated proliferation. This is precisely the outcome classical realism, drawing on the lessons of 1981 Osirak, 1998 Iraq, and 2003 Libya, would have predicted and sought to avoid.
Third: and most damaging, the regime change contradiction. The 2026 National Defense Strategy explicitly declared that the Department of Defense would no longer “be distracted by interventionism, endless wars, regime change, and nation building” — language that could have been lifted from a Rand Paul floor speech or a John Mearsheimer lecture. And yet the public case for Operation Epic Fury was suffused with regime-change logic. Trump’s Truth Social announcement at 2:00 AM on February 28, 2026 concluded with a direct message to Iranians that “the hour of your freedom is at hand.” As Lissner and Rapp-Hooper observe in Foreign Affairs, Trump himself had toured Saudi Arabia in 2025 declaring that “Western interventionists” and “nation builders wrecked far more nations than they built” — and now here was the same president calling on Iranians to “take over” their government. The contradiction is not incidental. It is structural.
The Anatomy of Strategic Impulse
To understand why “flexible realism” fails as a doctrine while succeeding as a brand, it is worth examining how the decision to escalate from Midnight Hammer to Epic Fury was actually made.
The diplomatic record is revealing. On February 6, 2026, Iran and the United States held indirect nuclear negotiations in Muscat, Oman, with CENTCOM commander Admiral Brad Cooper conspicuously present — a physical reminder of what the USS Abraham Lincoln represented offshore. By February 25, Iranian Foreign Minister Abbas Araghchi publicly stated that a “historic” agreement was “within reach.” On February 27 — one day before the strikes — Oman’s foreign minister said a “breakthrough” had been reached and that Iran had agreed to never stockpile enriched uranium and to full IAEA verification. The strikes came anyway.
This is not the behavior of a state executing a carefully sequenced coercive strategy. It is the behavior of a state in which the military option, once placed on the table, becomes its own justification. Real realism — the kind practiced by Eisenhower during the Suez Crisis, by Nixon and Kissinger during the opening to China, by George H.W. Bush during the Gulf War — is characterized precisely by its willingness to accept a less-than-perfect diplomatic outcome in order to preserve strategic flexibility and avoid uncontrolled escalation. The decision to strike when a deal appeared imminent suggests that the operative logic was not strategic calculation but something closer to what the president himself described as “I can’t take it anymore” — a phrase that would be alarming in any national security context but is disqualifying in the vocabulary of great-power strategy.
The Economic Blowback No Strategy Document Foresaw
The consequences for global markets have been severe and structurally different from previous energy shocks. As NPR and RBC Capital Markets analyst Helima Croft have observed, Iran achieved the closure of the Strait of Hormuz not through a traditional naval blockade but through selective drone strikes that made war-risk insurance effectively prohibitive. Tanker traffic dropped roughly 70 percent almost overnight. More than 150 freight ships anchored outside the strait. Iraq began shutting down production in its largest oil fields — not because of direct attack, but because it had nowhere to store oil it could not export.
The numbers tell a stark story:
- Brent crude has surged from pre-strike levels to trade above $110–$114 per barrel, up roughly 55 percent since the conflict began, with Iran’s IRGC threatening “$200 per barrel” if the strait remains closed.
- Goldman Sachs has warned that elevated prices could persist through 2027.
- Gulf oil production has collectively dropped by at least 10 million barrels per day as of mid-March, with Kuwait, Iraq, Saudi Arabia, and the UAE all affected.
- European natural gas benchmarks (Dutch TTF) have nearly doubled to over €60/MWh, forcing the ECB to postpone rate cuts and raise its inflation forecast.
- UK inflation is expected to breach 5 percent in 2026. The fertilizer industry — dependent on Gulf sulfur and LNG — faces cascading supply disruptions.
- The IEA, in language with no modern precedent, has labeled this the “greatest global energy and food security challenge in history.”
None of this was absent from pre-war analysis. The Congressional Research Service had documented Hormuz risks extensively. Energy analysts had modeled exactly this scenario. A doctrine genuinely anchored in national interest — one truly realist in the classical sense — would have weighted these costs heavily before pulling the trigger. The question is not whether the Iranian nuclear threat was real. It was. The question is whether a war that has handed China months of strategic breathing room, inflicted the largest energy shock in recorded history, threatened America’s Gulf allies with Iranian drone strikes, and killed six American service members and wounded nearly 300 more was the most strategically efficient way to address it. For classical realists, the answer is obviously no. For “flexible realists,” the answer seems to be: we’ll decide after the fact.
What True Realism Would Have Required
Here is the irony that genuine realists cannot escape: the vocabulary of realism has been hijacked by a foreign policy that violates nearly every precept of the tradition it claims.
Classical realism, from Thucydides through Morgenthau to Waltz to Mearsheimer, is built on a set of interlocking disciplines. It demands economy of force — the matching of means to interests, not ambitions. It requires threat prioritization — not all adversaries are equal, and the United States does not have the luxury of simultaneous wars of choice on multiple fronts when China commands the Indo-Pacific. It insists on respect for unintended consequences — the great-power realists of the Cold War were above all haunted by escalation; Kissinger’s entire career was a meditation on the gap between intent and outcome. And it demands what the theorist Barry Posen at MIT calls “restraint” — the disciplined willingness to accept imperfect outcomes rather than pursue maximalist ones that trigger counterproductive spirals.
On each of these counts, Operation Epic Fury is a realism test that the doctrine has failed:
- Economy of force: Two carrier strike groups, deep precision-munitions drawdowns, at least 290 wounded and six killed — for a theater that the NDS itself ranks behind the Indo-Pacific.
- Threat prioritization: Beijing observed the conflict from a position of strategic comfort. While Washington consumed its Indo-Pacific naval assets in the Gulf, China increased economic diplomacy with Gulf states and positioned itself as a potential mediator.
- Unintended consequences: Iran now has a “nuclear grievance” rather than a nuclear program — arguably a more dangerous condition, as the history of the NPT’s failures demonstrates. A decentralized Iranian nuclear capability, dispersed in ways that no strike can fully catalogue, may prove harder to contain than the centralized infrastructure that existed before June 2025.
- Restraint: The diplomatic record — the Oman breakthrough, the Geneva talks, Araghchi’s public statements — suggests that a negotiated settlement was available. It was not taken.
Congress, Credibility, and the Erosion of Democratic Legitimacy
A doctrine calling itself realism ought to take seriously the structural constraints on American power — including constitutional ones. The Senate voted 53–47 to block a war powers resolution that would have required congressional approval for the continuation of Operation Epic Fury, with only Senator Rand Paul breaking from Republicans. Democrats argued, with considerable constitutional grounding, that a month-long war against a sovereign state cannot be conducted solely on Article II authority. The administration’s decision to announce the strikes via a TruthSocial post at 2:00 AM — before any public congressional notification — was not merely a procedural failure. It was a deliberate assertion that in the age of “flexible realism,” the executive branch reserves the right to make war unilaterally whenever it judges the moment propitious.
This has strategic consequences that no White House press release can paper over. American credibility as a rule-of-law actor — the credibility that underpins alliance relationships, financial system dominance, and the willingness of neutral states to accommodate American power rather than hedge against it — erodes every time the United States demonstrates that its commitments are determined by presidential mood rather than institutional process. The Gulf states that absorbed Iranian drone strikes as collateral damage in a war they did not vote for — Saudi Arabia intercepting nearly 30 drones and a ballistic missile in a single night, Bahrain absorbing a strike on the USS Stena Imperative — may calculate their strategic alignments differently after this.
Russia, for its part, has conducted discussions with Washington about “cooperating to stabilize energy markets” — a framing that converts the Kremlin from sanctions-constrained aggressor into indispensable global-stability partner, precisely the geopolitical rehabilitation Moscow has sought for three years.
The Branding of Doctrine: How “Flexible” Became “Unprincipled”
The deepest failure of “flexible realism” is semantic. In classical geopolitics, the word “flexible” in a strategic doctrine is a warning sign. It usually means one of two things: either the doctrine is genuinely adaptive — capable of distinguishing between different threat environments and calibrating responses accordingly — or it is infinitely pliable, which is to say, not a doctrine at all but a post-hoc rationalization of whatever the executive branch decided to do.
Trump’s Iran policy has been both across different time periods, which makes the confusion worse. In 2025, after Operation Midnight Hammer, the administration appeared to be practicing something that resembled calibrated coercion: limited strikes, continued diplomatic engagement, explicit warnings tied to specific behaviors. This was, arguably, realism in operation. The shift to Epic Fury — full-scale war, regime decapitation, 9,000+ targets struck, the supreme leader killed — represents not an evolution of the doctrine but its abandonment in favor of maximalism. And maximalism, as Lissner and Rapp-Hooper argue in Foreign Affairs, is precisely what classical realism exists to constrain.
The administration’s use of “flexible” as a modifier thus performs a particular rhetorical function: it immunizes the doctrine against any specific criticism by defining coherence itself as a form of rigidity. When every escalation can be described as “flexible,” no escalation can be criticized as disproportionate. When every reversal can be reframed as adaptability, no position is ever definitively held. The result is not strategy. It is a permanent state of tactical improvisation dressed in the language of strategic thought.
What Comes After
There is, as Lissner and Rapp-Hooper acknowledge, a genuine opportunity embedded in the wreckage. The post-Trump foreign policy consensus — whenever it arrives — will need to be built from something more durable than nostalgia for the liberal international order of 1993. That order, as they argued in a 2025 Foreign Affairs essay, is “irreparably broken.” What replaces it must combine the best of realist discipline — economy of force, threat prioritization, strategic patience — with the institutional commitments that have historically magnified American power: alliance systems, multilateral frameworks, and the credibility that comes from behaving, over time, as a state that keeps its word.
The Iran war does not foreclose that possibility. But it does make it harder. The Strait of Hormuz crisis has demonstrated, painfully and expensively, that the global economy remains hostage to a 21-mile chokepoint that American military dominance could not protect without triggering the very disruption it was supposedly preventing. The nuclear question — Iran’s 400 kilograms of 60 percent enriched uranium, location unknown — has not been answered. The regime, now led by Mojtaba Khamenei, has not collapsed. And the United States has consumed military capacity, diplomatic capital, and economic goodwill that it will need in the Indo-Pacific for years to come.
“Flexible realism,” on the evidence of the past four weeks, is neither flexible nor realist. It is the foreign policy of a great power that has confused motion with strategy, force with achievement, and the destruction of an enemy’s military with the resolution of a strategic problem. Classical realism, from Thucydides to Kissinger, was always a counsel of limits — the recognition that power, however vast, is always finite, and that the statesman’s art lies in spending it wisely. Trump’s Iran war has spent it extravagantly, with an invoice in blood, treasure, and global stability that will come due long after the press releases stop.
The hour of freedom, as it turns out, is always more complicated than a TruthSocial post can convey.
Frequently Asked Questions (FAQs)
1. What is “flexible realism” in Trump’s foreign policy? “Flexible realism” is the term used in Trump’s 2025 National Security Strategy and 2026 National Defense Strategy to describe an approach to foreign policy anchored in coercive power and national interest, while rejecting what it frames as liberal-internationalist overextension. Critics argue the doctrine lacks coherent principles and serves primarily as a post-hoc justification for ad hoc decisions.
2. How does Operation Epic Fury contradict flexible realism’s stated principles? The 2026 National Defense Strategy explicitly rejected “regime change” and “endless wars,” yet Operation Epic Fury was publicly justified in regime-change terms, targeted Iranian leadership, and was launched despite a near-finalized diplomatic agreement — all of which contradict classical realist and the administration’s own stated doctrine.
3. What is the economic impact of Trump’s Iran war in 2026? The Iran war and effective closure of the Strait of Hormuz has triggered what the IEA calls “the greatest global energy and food security challenge in history.” Brent crude has risen approximately 55% to above $110 a barrel, Gulf oil production fell by at least 10 million barrels per day, European gas prices nearly doubled, and Goldman Sachs warned the shock could persist through 2027.
4. What did Lissner and Rapp-Hooper argue about Trump’s Iran policy? In their March 2026 Foreign Affairs essay “The False Promise of Flexible Realism,” Rebecca Lissner (CFR) and Mira Rapp-Hooper (Brookings) argued that the Trump administration’s doctrine collapses against Iran because it simultaneously claims to reject regime change while practicing it, prioritizes China as the pacing threat while committing naval assets to the Gulf, and presents maximalism as strategic flexibility.
5. What did Operation Midnight Hammer accomplish versus Operation Epic Fury? Operation Midnight Hammer (June 2025) consisted of limited, targeted strikes against Iran’s key nuclear facilities at Fordow, Natanz, and Isfahan. Operation Epic Fury (February 28, 2026) was a full-scale joint US-Israeli military campaign targeting thousands of Iranian military, missile, naval, and leadership assets, including the killing of Supreme Leader Khamenei.
6. How does Trump’s Iran war affect the US competition with China? The deployment of two carrier strike groups to the Persian Gulf, drawdown of precision munitions stockpiles, and years-long commitment of naval assets to a Middle East theater reduces the resources and posture available for Indo-Pacific deterrence — the strategic priority that both flexible realism and classical realism agree should be paramount.
7. What would classical realists like Kissinger or Mearsheimer say about the Iran war? Classical realists would likely critique the war on multiple grounds: the failure to exhaust a near-final diplomatic option, the contradiction between anti-regime-change doctrine and regime-change practice, the diversion of resources from the China challenge, and the underestimation of unintended consequences — particularly Iran’s likely long-term nuclear response.
