Following the inauguration of Brazilian president Luiz Inácio Lula da Silva in Brasília, Iran announced that it would send two of its warships to the South American country. The Russian state news agency, Sputnik, which has some other local proxies as its sounding board, recapitulated the announcement just two days before the ships were scheduled arrival of the ships to arrive—as published in the Brazilian government’s official journal. However, the ships never arrived.

What made Iran change its plans? Or rather, what were Iran’s plans?

Officially, Iran says that its ships, Dena—a Mowj-class frigate—and Makran—a former crude oil tanker converted into a helicopter carrier, now the largest ship in the Iranian navy—are on their way to the Panama Canal. The crossing of the Pacific Ocean would be the focal point for its plans to “go around the world.”

So far, it is not known what prompted the Iranians to change their plans and possibly their route. A seemingly isolated event may reveal part of the answer. On January 16, seven days before the Iranian ships arrived in the Port of Rio de Janeiro, the U.S. Air Force dispatched a WC-135R Constant Phoenix aircraft to South America. The operational purpose of the WC-135 is, notably, to identify atmospheric signs of nuclear activity—in other words, to be a “nuke sniffer.”

Dispatching such a plane on an unprecedented mission to collect a baseline reading of normal atmospheric conditions in South America raises eyebrows. The aircraft departed from Puerto Rico and collected atmospheric data off the coasts of Venezuela, Guyana, Suriname, French Guiana, and part of Brazil. It also traversed an area from the north up the Rio de Janeiro region, where the Iranian warships were due to be. The U.S. military did not intend for the mission to be secret: the plane’s transponder data was available to the public via flight monitoring platforms.

A second flight was carried out days later. The plane retraced its route around South America in the opposite direction, collecting data over the Caribbean, the northern coast of Venezuela, and over the waters of Colombia, Ecuador, and Peru. On this route, it flew over the Panama Canal, the presumed strategic destination of the Iranian flotilla.

This radiation survey over South America may have been a warning to Iran, creating problems for Tehran. Establishing baseline measurements of the region’s natural radiation levels would have become a hindrance if Iran had plans to use South America for nuclear testing. If the Iranian ships had been carrying radioactive material or weapons for offshore testing, possibly off of Venezuela, then the United States could identify anomalies in the atmosphere from its survey prior to the ships’ arrival in Brazil.

When it comes to Iran, everything is not what it seems. In 2005 and 2020, stories that Iran was producing missiles in Venezuela consumed the attention of researchers and governments looking for evidence that the two regimes were acting in concert to violate sanctions. While the West’s attention was diverted, Iran and Venezuela deepened their relationship through clandestine networks that possibly served to support the former’s nuclear program and transport materials, people, and financial and technological resources between the two regimes.

In 2020, Iran sent tankers to Caracas in defiance of sanctions and cast doubt about what the ships were actually carrying besides its declared fuel cargo. President Nicolás Maduro has never missed an opportunity to exacerbate tensions—for instance, he once publicly stated that he viewed the acquisition of Iranian-made long-range missiles as a “good idea.”

Iran’s efforts at concealment led many analysts to suspect, for example, that a network of tunnels had been dug under Venezuelan military installations in Maracay, in north-central Venezuela, to conceal missiles. Today, it would not be absurd to think that such facilities could be used for nuclear tests in partnership with Iran.

It is hard to say why Iran’s naval mission to South America has been “delayed”—or even interrupted. Maybe the mission was just another empty provocation. Maybe it was a smokescreen for clandestine activity, such as transporting nuclear material. If the first scenario is correct, Iran may have achieved what it wanted by causing tensions and forcing the United States to spend time, money, and attention on purely a propaganda operation. But if Iran had plans to deliver nuclear material to the region, then they might have found themselves cornered and were forced to reconsider their strategy. The “disappearance” and delay (or unannounced suspension) of its official port call in Brazil may certainly not have been a gamble in vain.

Leonardo Coutinho is an author and a senior fellow at the Center for a Secure Free Society.

Image: Shutterstock.