The Failure of American Isolationism in Iran and the Republican Choice for 2028
The case against JD Vance is not about a memorandum. It is about a policy, and about the kind of failure that falls on the leader who argued it into being.
A policy is different from a deal. A deal has terms and a clock and can be blamed on negotiators and circumstance. A policy is a sustained choice about how a great power behaves in the world, and it carries the signature of those who gave it voice. Vance did not invent American isolationism, nor does a vice president make American foreign policy alone. Donald Trump is president and the final decisions are his. But Vance became the most articulate champion of the isolationist turn inside the MAGA coalition, the figure who gave its instinct to withdraw from foreign entanglements the shape of a governing doctrine. Iran has now become the most consequential test of that doctrine.
And it has failed.
The doctrine itself deserves to be stated fairly. Its premise is not simply that America should abandon the world. It is that American power has been dissipated through open-ended commitments, unnecessary wars and alliances that too often transfer risk back to Washington. America should intervene only where its interests are unmistakable, use force narrowly when necessary, and seek an exit rather than allowing military action to acquire its own political momentum. There is wisdom in part of that critique. Iraq and Afghanistan gave Americans ample reason to distrust wars whose objectives expand faster than their possibility of success.
But restraint becomes isolationism when withdrawal itself is treated as strategy.
The test of such a foreign policy is whether disengagement delivers the stability its architects promise: whether the wars America leaves behind stay ended, whether the vacuums it creates remain empty, whether adversaries interpret restraint as closure rather than opportunity, and whether the allies asked to stand alone are still standing when Washington returns.
By that test, Vance’s Iran policy has failed outright.
The war begun in February with American and Israeli strikes was paused by an interim memorandum Vance helped negotiate and publicly defended. That memorandum has now collapsed back into open exchange, with Washington again striking IRGC targets along Iran’s southern coast and Iran answering against American interests in the region. A policy sold as an exit from war has instead produced its recurrence.
That is not merely a failed memorandum. It exposes the central weakness in the doctrine behind it. Disengagement works only when the adversary interprets disengagement as closure. The Islamic Republic does not. It interprets time, negotiation and strategic space differently.
Israel understood this better than Washington.
The interim memorandum was negotiated over Jerusalem’s objections, and Israel never shared the confidence placed in it by Vance and his allies. That disagreement was not simply between hawks and doves. Beneath it were two different theories of time.
For Vance, the interruption of war creates the possibility of peace. Stop the shooting, open diplomatic space, reduce incentives for escalation, and the political logic of war can gradually weaken. It is a reasonable theory when both sides ultimately prefer stability to confrontation.
Israel’s experience with the Islamic Republic has produced the opposite conclusion. A pause is not necessarily the beginning of peace. It can be another phase of conflict. Time allows an adversary to reconstruct missile stocks, command structures, proxy networks and military infrastructure. Negotiation can therefore function not as an alternative to strategy but as one of its instruments.
For one side, time de-escalates. For the other, time regenerates.
That distinction matters because a foreign policy cannot be judged by the intentions of the power practicing it. It must also account for how the adversary reads the same action. Restraint interpreted as restraint may reduce conflict. Restraint interpreted as weakness, exhaustion or permission can produce the opposite result. The error was not wanting the war to end. Every serious statesman should want wars to end. The error was confusing the desire to leave a conflict with the strategic conditions required to prevent the conflict from returning.
Marco Rubio represented the competing Republican instinct from the beginning: skepticism toward Tehran’s intentions, closer alignment with Israel’s reading of the regime, and reluctance to believe that a nuclear-capable and regionally aggressive Islamic Republic could be contained through patience alone. The distinction should not be exaggerated. Rubio serves the same president and has supported the administration’s major decisions. But the divergence between the two men is real enough to reveal two competing ideas of American power.
Iran is now testing both.
The consequences are already extending beyond Iran. Xi Jinping’s first visit to Egypt in a decade arrived as the war again exposed uncertainty about the durability of American strategy in the Middle East. Beijing did not arrive merely with trade agreements. Xi spoke openly about a different regional security order and a larger Chinese role in shaping it.
This illustrates a principle that isolationism repeatedly underestimates: great-power vacuums do not remain vacuums. They are exchanged.
When America reduces its presence in a strategically contested region, what follows is not necessarily less great-power politics. It can mean more Chinese power, more Russian influence, or greater freedom for regional actors whose interests diverge from Washington’s. Retrenchment therefore does not remove power from the international system. It redistributes it. A rival power does not need Washington’s invitation to occupy the political space Washington decides is no longer worth defending.
Then there is the moral debt, which Israelis and Iranians understand in different ways.
To call the Iranian people into the streets and then negotiate across a table with the regime slaughtering them — offering sanctions relief, oil waivers and reconstruction incentives as part of a settlement — is not merely a contradiction in messaging. It spends a form of strategic capital that cannot easily be recovered: trust.
Great powers possess credibility not only among governments but among populations. When Washington encourages a population resisting an adversarial regime, that population makes decisions partly on the assumption that American words carry political weight. If those words are followed by an accommodation that strengthens the same regime, the damage extends beyond those abandoned in that particular moment. The next population America asks to resist will remember what happened to the last one.
Reza Pahlavi has positioned himself as an alternative to the Islamic Republic and urged the world to weaken the IRGC rather than provide the regime the resources to reconstruct itself. Whatever one’s judgment of Pahlavi or Iran’s eventual political future, the strategic contradiction remains: Washington cannot simultaneously encourage resistance to a regime and rehabilitate that regime without paying a credibility cost.
A leader associated with a failed policy cannot defend himself simply by disclaiming each of its instruments. Vance can say that Trump made the final decision, that Witkoff negotiated parts of the agreement, that military commanders conducted the strikes, or that renewed escalation could not have been predicted. All of that may be institutionally true and still miss the political question.
Presidents own administrations. But politicians also own the doctrines they ask a country to trust.
Vance made restraint abroad part of his political identity. He argued that the United States had confused intervention with strength and military commitment with strategy. That argument deserved a test. Iran provided one. The problem is not that restraint was tried and war nevertheless occurred. No doctrine eliminates contingency. The problem is that the assumptions on which the doctrine rested have themselves been contradicted: the pause did not become peace, Iran did not treat disengagement as closure, America’s allies did not feel more secure, and the strategic space Washington sought to leave did not remain empty.
That record matters beyond the present war.
Trump cannot run again, which means the vice presidency in this term is not simply an office. It is the default staging ground for 2028. Vance begins with the enormous advantage of proximity to Trump, the loyalty of much of the MAGA coalition and the institutional visibility of the vice presidency. But inheritance is not entitlement.
The Republican primary of 2028 should therefore become more than a contest of personalities. It should be a referendum on what America learned from Iran.
The question is not whether JD Vance should be expelled tomorrow from an administration whose policies ultimately belong to its president. “Vance Must Go” means something more consequential than that. A man asking to inherit a political movement must also inherit responsibility for the doctrine he helped persuade that movement to embrace.
Iran was Vance’s test. The promised restraint did not produce disengagement. The pause did not produce peace. The vacuum did not remain empty.
The question is no longer whether Vance survives as vice president.
It is whether the party that watched this fail hands him its future.
