Black Swan Scenarios in U.S.-Iran Relations During Trump’s Second Term

In the volatile arena of international politics, the return of Donald Trump to the White House has amplified global uncertainty, particularly in relation to adversarial states like Iran. Unlike conventional geopolitical shifts, the current moment is defined by unpredictability, ideological rigidity, and institutional fragility—hallmarks of what many now refer to as a “wrecking ball” approach to diplomacy. Trump’s second term has already begun to unravel established norms, defy diplomatic protocols, and reorient U.S. foreign policy around coercion rather than consensus. In this environment, the U.S.-Iran relationship, long marred by distrust and antagonism, stands at the edge of several precipices. While ongoing tensions and proxy conflicts dominate headlines, it is the “black swan” scenarios—high-impact, low-probability events—that may ultimately shape the future of US-Iran relations in ways both sudden and profound.

This short reflection explores four such scenarios: (1) a major terrorist attack inside the United States with Iran cast as the likely perpetrator, (2) the collapse of the transatlantic alliance and a resulting geopolitical realignment between Iran and Russia, (3) the fracturing of U.S.-Israel alliance due to a new nuclear deal with Iran, and (4) a catastrophic nuclear accident in the Middle East. Each of these scenarios presents unique challenges and opportunities, but together they reveal the fragility of an international system increasingly shaped by improvisation, polarization, and the erosion of long-standing alliances.

The Perfect Scapegoat: A Terrorist Attack on U.S. Soil

A major terrorist attack inside the United States remains one of the most feared contingencies in national security planning. If such an attack were to occur under Trump’s second term, the political consequences could be swift and severe—especially if Iran is perceived, correctly or otherwise, as complicit. In a post-9/11 political culture still shaped by vengeance, and in an administration that prizes forceful responses over deliberation, the temptation to use Iran as a scapegoat could trigger a chain reaction of escalation.

Iran’s historical ties to proxy groups such as Hezbollah, as well as its rhetorical antagonism toward the United States and Israel, make it a convenient—if not always accurate—target for blame. Even in the absence of direct Iranian involvement, the administration could seize on circumstantial evidence or intelligence interpretations to justify punitive military action. The recent history of misinformation and politicized intelligence (as seen in the lead-up to the Iraq War) underscores how such a scenario is not only plausible but perilously easy to set in motion.

The ramifications would be immense. An American retaliatory strike on Iranian territory could provoke regional war, galvanize Iranian hardliners, and destroy any remaining hopes for diplomacy, let alone nuclear negotiations. More dangerously, it could usher in a series of overt and shadowy military escalations not just between Iran and the United States but also involving Saudi Arabia, Israel, Iraq, Yemen, Syria, Lebanon, and even Jordan and Egypt. In such a scenario, global energy markets, regional stability, and nuclear nonproliferation regimes could all get caught up in the general conflagration between the chief antagonists. 

Transatlantic Collapse, Eurasian Realignment

A second black swan scenario lies in the collapse of the U.S.-EU security alliance, a possibility increasingly discussed among analysts who note growing transatlantic rifts over tariffs and trade, defense spending, the war in Ukraine, election interference, and the general foreign policy of the European Union. The Trump administration’s apparent disdain for NATO and the EU, coupled with its transactional approach to diplomacy, has already significantly eroded the foundations of the liberal international order.

Should the growing rift give way to a full collapse of security relations between the EU and the U.S., Iran could emerge as a beneficiary—especially if it deepens a geopolitical realignment already underway between Tehran, Moscow, and Beijing. The Iran-Russia relationship, historically pragmatic but cautious, could deepen as both countries face intensifying economic pressures from the West, President Trump’s lukewarm relations with Vladimir Putin notwithstanding. Enhanced military cooperation, energy deals, and intelligence sharing are all on the table. China, too, may intensify its Belt and Road investments in Iran, further embedding the country within an alternative economic order.

Such a scenario would not only weaken U.S. leverage over Iran but also isolate Washington in its maximum pressure campaign. Without European support, the United States would find it far harder to maintain sanctions coalitions or present a unified front in nuclear negotiations. Iran, emboldened by its new alliances and economic lifelines, could take bolder steps toward nuclear threshold status or more aggressive regional behavior—confident that Washington’s traditional diplomatic toolkit is no longer operative.

A U.S.-Iran Nuclear Deal that Fractures the U.S.-Israel Alliance

Among the unthinkable but plausible shocks to the U.S.-Israel relationship, few would be as destabilizing—or as unexpected—as a Trump-brokered nuclear deal with Iran that ignores, or directly rebuffs, the fierce opposition of Israeli Prime Minister Benjamin Netanyahu. In a second Trump term already defined by unpredictability, such a reversal—where Trump pivots from “maximum pressure” to a negotiated agreement—would constitute a black swan event: an unforeseen rupture with high-stakes consequences for regional order and alliance structures.

This would mark a fundamental break from both Trump’s prior policy and the shared U.S.-Israel posture on Iran. Throughout his first term, Trump echoed Netanyahu’s hardline stance, withdrawing from the 2015 Joint Comprehensive Plan of Action (JCPOA) and intensifying sanctions. For Netanyahu, Iran’s nuclear program is not just a strategic challenge, but an existential one. Any American compromise that allows Iran to retain enrichment capacity or reenter the global economy would, from his perspective, embolden Tehran’s ambitions and leave Israel exposed.

The political and strategic consequences of such a deal would be immediate and profound. Netanyahu, who has closely aligned himself with Trump for years, would likely see this as a deep betrayal—one that not only undermines Israeli security policy but also shatters the perception of Trump as Israel’s staunchest defender. The Israeli political establishment, especially on the right, could erupt in outrage. In turn, U.S. domestic politics would be roiled, with pro-Israel advocacy groups, congressional Republicans, and evangelical leaders forced into an uncomfortable dilemma: support the president, or side with Israeli objections.

More dangerously, this rift could spill into operational realms. Israeli officials, convinced that diplomacy has failed and unwilling to trust Iran’s compliance, might resort to unilateral action—cyberattacks, sabotage, or even preemptive strikes on Iranian nuclear facilities. The risk of escalation would rise exponentially, especially if Iranian retaliation draws the U.S. into a conflict it hoped to avoid. This dynamic—of a U.S. peace overture triggering war through its closest regional ally—is precisely the kind of non-linear, high-impact scenario that defines a black swan.

Such an event would also challenge the broader architecture of the post-Cold War Middle East. A visible fracture between Washington and Jerusalem would invite regional realignment. Israel might double down on military cooperation with Gulf states wary of Iranian resurgence. Conversely, Iran could interpret the U.S. overture as a green light for expanding its regional influence, further destabilizing Lebanon, Syria, and Iraq. America’s diplomatic credibility would suffer, caught between the optics of reconciliation and the reality of confrontation.

In this imagined but plausible future, a Trump-led nuclear deal with Iran does not just reset the terms of nuclear diplomacy—it detonates assumptions about the permanence of the U.S.-Israel alliance. That such a fracture could come at the hands of the most pro-Israel president in American history makes it all the more unexpected—and all the more dangerous.

A Nuclear Accident

A final black swan scenario is a nuclear accident—whether involving Iran, Israel, or another regional actor—that jolts the international system. Such an event could take many forms: a malfunction or an act of internal sabotage at a reactor site or enrichment facility, an intentional Israeli strike on a suspected nuclear site, or even a radiological incident involving a third party like Saudi Arabia or the UAE, both of which have ambitions for civilian nuclear programs.

In the current environment of frayed communication channels and weakened multilateral institutions, the response to such a disaster could be chaotic. Iran might accuse Israel or the United States of sabotage; Israel could interpret the incident as justification for preemptive strikes; and international agencies like the International Atomic Energy Agency (IAEA) could find themselves sidelined or ignored.

The Trump administration’s hostility toward international institutions would only exacerbate the crisis. Rather than seeking cooperative containment or investigation, Washington might exploit the moment to pressure Iran further or to justify an aggressive posture. Conversely, if Iran is seen as the victim of sabotage, it could earn international sympathy and shift the global narrative in its favor, undermining U.S. credibility.

The broader risk is that a nuclear accident, far from galvanizing caution, could desensitize the world to nuclear escalation or embolden regional actors to gamble on dangerous strategies. In such a climate, the line between accident and intentional provocation could blur beyond recognition.

Planning for the Unplannable

Each of these black swan scenarios underscores the dangerous unpredictability of the current moment in U.S.-Iran relations. While none is inevitable, all are plausible in a world where diplomacy has been supplanted by improvisation, alliances are fraying, and leadership is both unstable and ideologically extreme.

The Trump administration’s second term represents more than just a continuation of past policies; it is a fundamental rupture with postwar diplomatic norms. By sidelining expertise, hollowing out institutions (especially policy processes), and privileging spectacle over substance, the administration has left the U.S. ill-equipped to anticipate or manage high-impact shocks. In such an environment, black swan events are not mere hypotheticals—they are the logical outgrowths of a system under stress.

For U.S. policymakers, the imperative is clear: to reestablish credible deterrence, rebuild institutional capacity, and reengage allies before crisis turns into catastrophe. For Iran, the challenge is to navigate between provocation and restraint, lest it miscalculate the intentions of an erratic superpower. And for the rest of the world, the lesson may be the most sobering of all: in an age of wrecking ball diplomacy, the stability of the international system can no longer be taken for granted.