The Tehran government has announced the arrest of seventeen Iranian citizens caught spying for America’s Central Intelligence Agency (CIA). Some of those arrested have already been sentenced to death. It is the third major roll-up of CIA agents in Iran that I have been aware of, the first occurring in 1991 involved 20 American agents. The second episode in 2011 led to the arrest of 30 spies. The earlier arrests reportedly eliminated what were presumed to be the entire networks of American agents operating inside Iran and it is to be presumed that the recent arrests will have the same impact.

The Iranians presented a considerable quantity of evidence, including photos and business cards of US government officials, to back up their claim of American spying but President Trump dismissed the report as “totally false” and “just more lies and propaganda” — while Secretary of State Mike Pompeo said: “I would take with a significant grain of salt any Iranian assertion about actions that they’ve taken.”

Iran’s press release on the arrests together with a briefing by an intelligence official supplemented by local media coverage provided some of the details. The seventeen reportedly had “sophisticated training” but those who had sabotage missions did not succeed. Other objectives included “collecting information at the facilities they worked at, carrying out technical and intelligence activities and transferring and installing monitoring devices.”

Some of the agents had reportedly been recruited by falling into what is referred to as a “visa trap” set by the CIA for Iranians seeking to travel to the US. This has long been the preferred tool for recruiting Iranian agents. The intelligence official handed out a CD with a video recording of an alleged CIA case officer speaking to an Iranian target, which was presumably recorded secretly. The video shows a blonde woman who speaks Persian with an American accent. The disc also included names of several US embassy staff in Dubai, Turkey, India, Zimbabwe and Austria who Iran claims were involved in the recruitment and training of the Iranian spies.

How exactly did the recruitments take place as there is no US Embassy in Tehran and few Americans resident in the country? Many of the Iranians were targeted when they walked into an American Embassy in a country to which they are free to travel, which includes Turkey and Dubai. In the words of the Iranian intelligence official, “Some were approached when they were applying for a visa, while others had visas from before and were pressured by the CIA in order to renew them.”

Others were targeted and recruited as spies while attending scientific conferences around the world. Those recruited received promises of money, eventual resettlement and a job in the US or medical assistance. To maintain contact with its agents inside Iran, the CIA would reportedly conceal spyware and instructions in containers that look like rocks, which would be planted in city parks or in rural areas. The Iranian agents would then recover the material, which might include false identification documents. It should be observed that fake rocks are a standard espionage tool. They are hollowed out to conceal spy-gear and communications. After they are in place, a signal is made to alert the agent that there is something ready to be picked-up. In the trade they are referred to as “dead drops.”

Why does the United States continue to spy on Iran with such ferocity? The Mullahs became a major intelligence target for Washington in the wake of the 1979 US Embassy hostage crisis, in which fifty-two American diplomats and intelligence officers were held for 444 days. The CIA mounted a major intelligence operation run from Europe that collected a wide range of information on the Iranian government and, increasingly, on its technical capabilities, including a suspected nuclear development program. In 2015 the CIA under President Barack Obama and Director John Brennan ramped up collection efforts against Iran as part of the verification process for the Joint Comprehensive Plan of Action (JCPOA). More recently, Mike Pompeo, when CIA Director, further increased efforts against Iran when the Trump Administration withdrew from that agreement in the belief that Iran represented a rogue nation and a threat to United States interests and allies. In reality, of course, there is no real American vital interest relating to Iran and Trump has been acting on behalf of Israel and Saudi Arabia, both of whom are hostile to Iran as a regional rival.

But running intelligence operations in a country without a US Embassy to serve as a base for spies proved difficult. Many spies have been caught, by one Iranian estimate, 290 agents arrested in recent years. Most often the exposure of the spies has been due to human error or technical problems in communications. Iran has benefited by boasting of those arrests and has long promoted its capacity to uncover American spy rings in the country. As the New York Times reports, Iran has recently aired a documentary featuring efforts to expose and rid the country of the CIA agents working there.

A recently produced and very popular Iranian fictional television series called “Gando” has also introduced the narrative of a perpetual fight against American spies into the country’s popular culture. The show features brave Iranian intelligence officials in pursuit of an American spy posing as a journalist.

According to a Yahoo News investigation, Iran was in 2009 enraged by reports that the CIA had possibly penetrated its nuclear program and its counter-intelligence agents immediately went on the hunt for moles. By 2011, Iranian officials had uncovered and arrested a network of 30 CIA sources, a fact that US officials later confirmed. Some of the accused informants were executed. The Iranian government was able to find the operatives because of failures in the systems and techniques that the CIA agents used to communicate with the agents. Once a flaw in communications is detected, it is possible to exploit that so one can sit back and wait and watch for all those linked to the network to reveal themselves.

One might observe that the continued massive American “maximum pressure” spying effort directed against Iran is a bit of an anachronism. It is agreed by nearly all observers that Iran has no nuclear weapons program and is unlikely to start one. The sanctions put in place against the country unilaterally by the US cannot produce a popular uprising that will bring down the regime, but they have indeed hurt the country’s economy badly and the people are suffering. Iran’s military cannot stand up against its neighbors, much less against the United States, and its ability to meddle in the affairs of its neighbors is extremely limited.

So, it is probably just as well that Iran has again rolled up most of the American spies in the country, though it will be a tragedy for the men and women involved. Many critics of the Agency have argued that the CIA has forgotten how to spy in an age of drones and electronic surveillance, which may be true. Certainly, the CIA record regarding Iran is nothing to brag about.