There is growing concern that the United States and Iran could enter direct military conflict following Israel’s preemptive strikes on Iranian nuclear facilities on June 13, 2025. While any combat would likely be confined to Iranian territory, this escalation is already reviving fears that Iran might attempt to strike the U.S. homeland—potentially through infiltration at the southern border.

These fears are not new. In 2023, two Iranian nationals on a U.S. security watchlist were apprehended at the southern border, fueling divergent narratives. Border hawks view such cases as evidence of a broader Iranian threat, while libertarian critics counter that data consistently show minimal terrorism risk from Iranian migrants.

This report evaluates both perspectives by examining irregular migration patterns of Iranian nationals across the Western Hemisphere. While security concerns are legitimate, three factors make border infiltration unlikely: (1) irregular migration by Iranians has sharply declined since its early 2025 peak; (2) Iran would likely prefer less scrutinized entry routes than the heavily monitored southern border; and (3) such an operation would invite overwhelming U.S. retaliation—something Tehran seems intent to avoid.

Recent migration trends signal decline

Iranian irregular migration through Latin America has historically been limited and inconsistent. For most of the early 2020s, only a few dozen Iranians were encountered per month crossing Colombia, Panama, Honduras, and Mexico.

When spikes have occurred, they have generally coincided with political unrest in Iran. A modest increase in September 2023 aligned with the anniversary of Mahsa Amini’s death and the “Woman, Life, Freedom” movement. A larger surge—from 287 encounters in June to 539 in July 2024—paralleled Iran’s presidential election and intensified political suppression. 

Despite a record spike in January 2025, Iranian encounters dropped to recent lows by May 2025—even as Iran’s economy worsened, with the rial losing 60% of its value and inflation topping 30%. This suggests a fundamental shift in Iranian migration dynamics rather than a temporary lull.

The complex and arduous routes taken by Iranian migrants help explain why their numbers remain low compared to other nationalities—and why these pathways are impractical for state-sponsored infiltration.

Colombian data shows that 96% of Iranians entered Colombian territory via Ecuador, with fewer than 1% arriving from Venezuela, despite visa-free access and direct Tehran-Caracas flights. Regional patterns indicate that most Iranians fly to São Paulo via Istanbul, then travel overland through Peru, Ecuador, Colombia, and the Darién Gap before continuing through Central America to Mexico.

As a result, there are extensive monitoring and interdiction opportunities Iranian migrants face across multiple national jurisdictions. Since January 2022, CBP has recorded approximately 1,650 encounters with Iranian nationals at the southwest border—evidence of detection, not evasion.

Demographic data supports both humanitarian and security-related interpretations. Most Iranian migrants are single men, a trait common among economic migrants but also relevant to security screening. According to data from Colombia, Honduras, and the U.S. court system, about 75% of Iranian migrants are male and 25% are female–but crucially, 66% are over age 30, and an additional 10% are minors, making them outside of the typical age range for operatives in covert missions. 

U.S. immigration court records further support a humanitarian reading. The share of Dari speakers among Iranian migrants doubled—from 6.5% to 13% between FY2023 and FY2025–suggesting the presence of –Afghan refugees holding Iranian documentation. Media reports also highlight cases involving religious minorities, reinforcing that these migrants are fleeing persecution, not mounting attacks.

Security assessment and alternative pathways

Despite largely humanitarian motivations, certain aspects of Iranian migration raise legitimate security concerns. São Paulo is a hub for Iranian document forging networks, complicating efforts to track their movement across the region.

These forged passports—often mimicking Israeli documents—can serve dual purposes: enabling travel for genuine migrants while helping Iranian intelligence refine their tradecraft. But overuse has attracted scrutiny, making these methods increasingly risky and less reliable.

The Tri-Border Area (TBA) between Argentina, Brazil, and Paraguay–where Hezbollah maintains a known presence–could hypothetically aid Iranian movement. However, Hezbollah’s activities there center on fundraising and illicit trade, not human smuggling or terrorist infiltration.

The 2019 case of Mohsen Khademi Manesh illustrates both the capabilities and limitations of these networks. Manesh helped forge Brazilian documents for suspected al-Shabaab operatives, demonstrating the ability of these networks to create passable forgeries. Yet the network’s eventual disruption through Brazilian-U.S. intelligence collaboration underscores the persistent monitoring such operations face.

Irregular migration routes are ill-suited for covert infiltration. The Iranian journey typically takes 3-6 months, spanning seven countries and various levels of enforcement. Migrants face health emergencies, criminal exploitation, and must rely on financial systems—all of which increase their visibility to authorities.

Given these logistical hurdles, Iran would more likely turn to alternative methods: using forged passports, from non-flagged countries, maritime smuggling, or recruiting individuals already inside the U.S.–not sending operatives through a relatively unreliable and time-intensive route to the southern border.

Finally, Tehran has compelling reasons to focus its limited resources on regional operations. It is currently trying to localize its conflict with Israel and deter direct U.S. involvement. An attack on U.S. soil—especially one tied to irregular border entry—would provoke overwhelming retaliation and bolster hardline political narratives.

While U.S. agencies should continue monitoring known Iranian migration routes and forgery networks, the likelihood of infiltration via the southern border remains low. In the broader landscape of Iranian threats, it should be treated as a secondary concern—not a frontline vulnerability.