The storyline sounds like a B-grade movie with a dark comedic angle. An immigrant made less-than-good gets mixed up with Mexican drug cartels in a slow-moving plot to blow up the Saudi ambassador in Washington, D.C., on behalf of the Iranian intelligence service. To a public expecting Bondian dash, or al-Qaeda-like determination, it all seems strange, even half-baked. The Coen brothers should get working on the script.

Mansour Arbabsiar, now facing a raft of indictments, seems destined to go down in the annals of espionage and terrorism as one of the less intriguing characters. After three decades in Texas, the 56-year-old Iranian and naturalized American appears a lot like his neighbors. A car salesman calling himself Jack, he has behind him several jobs, none too successful, a couple broken marriages, some financial challenges, a few brushes with the law and a distinct lack of fanaticism about anything, including religion. A zealot eager to wage jihad he was not.

Yet he did reportedly have a cousin back home who was high up in the Iranian security services, specifically the Revolutionary Guards Corps, the powerful Pasdaran. According to the U.S. Department of Justice, this got the unremarkable Arbabsiar in touch with the Pasdaran’s elite special-operations arm, the sinister Quds (Jerusalem) Force. Much about the case remains murky, but the detailed indictment released on October 11 indicates that the U.S. government possesses a wealth of information about the plot, presumably based on signals intelligence (SIGINT), including money transfers and telephone conversations which leave no doubt that the plan, no matter how strange sounding, was real and not the figment of Arbabsiar’s imagination.

Many commentators have already noted that the tradecraft on display in this case seems remarkably primitive given what we know about Iran’s normal modus operandi. Certainly the Quds Force is an accomplished and unpleasant service, responsible for assassinations and bombings in many countries. For nearly three decades, it has been the covert arm of Iran’s revolution, striking down adversaries abroad. It has carried out hundreds of attacks, many fatal, on Iranian émigrés, and occasionally foreign enemies, worldwide. Its role in Iraq and Afghanistan has been particularly criticized by U.S. officials, who are unhappy that Quds Force operatives have managed to pull off anticoalition operations, directly or more often through proxies, almost unscathed. The number of American troops killed or maimed by Quds Force weapons in recent years is at least in the many hundreds. Qasem Suleimani, the force commander, is rightly viewed as the most powerful man in Baghdad, de facto responsible for Iranian policy in Iraq. Quds Force officers are routinely sent abroad as “diplomats,” and two recent Iranian ambassadors in Baghdad have been force members. Its hidden hand in Iranian policy, powerful for decades, has been growing stronger in recent years.

Suleimani has been named by the U.S. government as the ultimate driver of the Arbabsiar plot, which the Americanized car salesman termed Operation Chevrolet. This accusation, if true, has stunning implications. It is difficult to determine which is more disturbing—that Ayatollah Ali Khamenei, Iran’s supreme leader, would approve a brazen act of terrorism in America’s capital or that Qasem Suleimani would give the go-ahead for the operation without approval from the top. Answering this question is critical but challenging—and perhaps impossible at this point.

Assessing Suleimani’s motivation is nearly as important. Is this a response to U.S. and Israeli pressure on Iran over its nuclear program? Is it part of the widening Sunni-Shia war across the Middle East, which easily boils down to a Tehran-versus-Riyadh contest? Is it payback for the recent untimely and violent deaths of several leading Iranian nuclear scientists, acts which Tehran insists are the work of Israel and/or America? How about payback for the Stuxnet virus, which a year ago devastated Iranian nuclear work—another operation the Iranian regime blamed on Israel and its American big brother? Perhaps most worrisome, is this the Quds Force lashing out on its own—for several and perhaps all of the above reasons—when it feels Khamenei will not react aggressively enough? Answering this question ought to drive the American response to Iran’s failed effort to execute an act of war in our nation’s capital.

However, it should be noted that, although the Quds Force is a capable secret service which has pulled off complex operations far from home—most infamously the bombings in Buenos Aires of the Israeli embassy (1992) and the AMIA Jewish cultural center (1994), which between them killed 114 and injured hundreds more—Iran also has a history of less complicated but equally bloody activities, including in the United States. The last Iranian assassination in America sheds light on the varying quality of Tehran’s covert operations. In July 1980, Ali Akbar Tabatabai, a prominent Iranian émigré and opponent of the new Islamic Republic, was gunned down in his driveway in Bethesda, Maryland, by a black man dressed as a postal worker.

The “mailman” was Dawud Salahuddin, born David Belfield in North Carolina thirty years before. Raised in a Baptist family on Long Island, Belfield converted to Islam as a student, motivated partly by black nationalism, and soon fell in with a violent clique. Belfield adored the Iranian revolution as much as he hated America, and hevolunteered his services to Tehran’s intelligence service, which tasked him with killing the troublesome Tabatabai. Belfield had hoped to murder a more prominent target—he preferred Henry Kissinger or Kermit Roosevelt, the former CIA official who had helped orchestrate the 1953 Iranian coup against Mohammad Mossadeq—but he followed Tehran’s orders, receiving $5,000 for the hit.

After the killing, Belfield fled to Iran, where he remains more than three decades later. He has worked various jobs, reportedly fought in Afghanistan against the Soviets in the 1980s, and seems homesick. More than once he has contacted American officials about returning home, without success. Strangely, Belfield/Salahuddin appeared in the 2001 film Kandahar, a successful production set in Afghanistan that premiered at Cannes.

For decades the U.S. government has been reluctant to address Iran’s robust state terrorism program in any detail, even when it targets Americans and close U.S. allies. While Iran often uses cutouts for its terrorism, above all Hezbollah, Tehran’s footprint has frequently been detected by U.S. intelligence. Although the Reagan administration knew of Iranian intelligence’s key role behind the October 1983 bombing of the U.S. Marine barracks in Beirut, which killed 241 American servicemen, it did nothing against Tehran, setting a pattern which has held to the present day.

The Quds Force’s tight relationship with Hezbollah has been officially minimized by most Western governments, although it is an open secret that has been well understood by U.S. intelligence for decades. Hezbollah’s operations wing since its creation almost thirty years ago has been a wholly owned subsidiary of the Pasdaran, while its founder and head until his death in 2008, Imad Mughniyeh, arguably the most prolific terrorist of modern times, was exceptionally close to Tehran and loyally followed the orders of the regime.

The Quds Force has had dealings with many terrorist groups over the years, including Hamas, and most intriguingly with al-Qaeda. Although U.S. intelligence has been aware of some sort of Iranian relationship with al-Qaeda since 1996, mainly through Hezbollah intermediaries, this question has been considered too hot to touch by many U.S. officials, despite its obvious importance. Even the 9/11 Commission largely punted on this knotty issue, viewing only a limited amount of information during its investigation, despite the fact that the National Security Agency possessed considerable detailed reporting indicating an operational relationship between the 9/11 plotters, Hezbollah, and Iranian intelligence. As one of the 9/11 Commission staff members noted in 2010, “It’s always been frightening to me to consider what is still at the NSA, whatever we never had time to see,” not least because the NSA, the SIGINT arm of the intelligence community, is responsible for the lion’s share of actionable intelligence in the U.S. government. Although the commission report recommended further investigation of Iran’s ties to al-Qaeda, since the commission closed down in 2004 there has been no reexamination of the NSA files in question.

The mysterious Arbabsiar case offers an opportunity for the Obama administration to ask, and possibly answer, tough questions about Iran and terrorism which the Bush administration showed little ardor to pursue. To be fair to U.S. officials and investigators, their unwillingness to think hard about the Quds Force and its dirty work abroad mirrors the unfortunate habits of most terrorism scholars, who prefer to ignore the major issue of state sponsorship and involvement in international terrorism. Few outside experts acknowledge, much less explore, the fact—well understood by counterintelligence officers—that many intelligence services conduct terrorism through proxies, and most terrorist groups have discreet ties to one or more secret services.

Elements in the Bush administration in the eighteen months after 9/11 brought discredit on this issue with their ham-handed efforts to tie Saddam Hussein’s Iraq to al-Qaeda—though it has now been firmly established from captured documents that Saddam’s intelligence services had strong ties to many terrorist groups, just not Bin Laden’s. Nevertheless, this week’s revelations ought to force an overdue investigation of Iran’s long-standing ties to international terrorism as well as to the broader issue of state linkages to terrorism. Better late than never.