I had no reason to be suspicious. I receive dozens of media requests a week and this one was no different. Last summer, I received an email from someone who said that he was a journalist—from an outlet I hadn’t heard of before—and that he wanted to ask a few questions about the Iran nuclear deal. At the time, my book on the subject, Losing an Enemy: Obama, Iran, and the Triumph of Diplomacy, had just appeared.

I had no idea that the man in question was working for Black Cube, a private Israeli intelligence firm now best known for its expertise in intimidating and silencing women who had been sexually abused by Harvey Weinstein, as Ronan Farrow has reported in The New Yorker. But this time, Black Cube—which offers its clients the skills of operatives “highly experienced and trained in Israel’s elite military and governmental intelligence units”—was reportedly working not for Weinstein, but for a group of presidential aides or allies. The operation, as Julian Borger of The Observer (which first broke the story) said, was “commissioned by people close to Donald Trump,” and its aim was to find or fabricate incriminating information about former Obama administration officials, as well as people and organizations that had a part in securing the Iran nuclear deal. Farrow’s reporting has established that White House foreign policy advisers Ben Rhodes and Colin Kahl were targets of Black Cube’s subterfuge.

At the time, I didn’t know any of this. I thought that I was giving an interview about the intricacies of the nuclear negotiations. After some initial small talk, we soon started discussing the deal. The interviewer sounded young over the phone, probably no more than twenty-five or twenty-six. He didn’t come across as having a particularly strong grasp of the subject, but he spoke with confidence.

I took the opportunity to steer the conversation toward one of the conventional wisdoms I challenge in my book: the idea that the pressure from sanctions forced Iran to finally show flexibility on the nuclear issue, paving the way for a deal. In the course of my research, I had interviewed almost all of the officials from the Iranian and American sides involved in the secret negotiations. What I learned about those talks was that it was primarily the US’s willingness to accept uranium enrichment on Iranian soil (that is, accepting Iran’s bottom line, since Tehran refused to give up its enrichment technology) that made Iranian flexible, not the pressure from sanctions.

Then, suddenly, the conversation took an unexpected turn. Instead of asking questions, the Black Cube operative started making assertions and pushing me to give statements affirming them. The real reason Obama had agreed to the nuclear deal, he insisted, was because of the financial interests of certain members of his White House staff.

“There are desirable side-effects,” I said in an attempt to shift the conversation to more factual grounds, “and even though it isn’t central, a positive side-effect of the deal is that it reduces America’s dependency on Saudi Arabia and enables Washington to get tough with Riyadh’s support for jihadi terrorism.”

“So you know there might be other interest then, other than national and security interests,” he shot back.

“But these are not central objectives, and they certainly are not financial,” I responded in frustration. I had been in close contact with the administration throughout the negotiations as an informal adviser and I had not seen a shred of evidence that financial and economic interests figured at all in their calculations on Iran.

“On the contrary,” I continued, “the administration actively avoided involving the American private sector in the effort to secure a nuclear deal—even though administration officials knew that their lobbying power could prove decisive in saving the deal from congressional rejection.” My many conversations with Obama officials during this period made it clear that the president saw the Iran nuclear negotiations strictly as an arms control issue and did not encourage lobbying by private businesses so that lawmakers would not doubt that nonproliferation was the central motive for the deal.

But my interviewer would not back down. He kept returning to the idea that secret financial interests had driven the negotiations and tried to goad me into agreeing with him. Once he realized that I would not meet his conspiracy theory halfway, he abruptly cut the interview short.

I didn’t think much of it. I was annoyed, but neither surprised nor alarmed. Conspiracy theories about the deal have been common enough. Israel’s prime minister, Benjamin Netanyahu, argued that it would pave Iran’s path to a bomb—an absurd claim. And Trump himself loves to repeat the lie that Iran got $150 billion from the United States for agreeing to the deal. The notion that the Obama administration had any financial interest in the nuclear deal was a preposterous conspiracy theory—but not obviously more so than those promoted by the Israeli prime minister and the current US president.

I had completely forgotten about the encounter until this past weekend. Then, The New Yorker’s Ronan Farrow contacted me and, to my amazement, read back portions of my conversation with the fake journalist; Farrow had obtained a copy of Black Cube’s transcript from his sources. What I had thought was a misguided, conspiracy-minded reporter had been one of the firm’s operatives, Farrow explained.

After the initial shock, it started to make sense. Several weeks after the 2016 election, I had received a chilling message from a person in the US intelligence community (via an intermediary). The team around Donald Trump, my contact warned, was going to try to discredit me and my organization, the National Iranian American Council, and some of our allies. We had been staunch supporters of the nuclear deal, and we were now considered obstructions that needed to be removed in order to kill it. As a first step, the intermediary advised me, I need to get a much more secure phone, which I did.

Now, it appeared, evidence of this targeting had emerged. But this experience was not without precedent; it was the latest phase in a longstanding campaign by pro-war, neoconservatives like Daniel Pipes, Kenneth Timmerman, and Michael Rubin to intimidate, defame, and silence me and my organization. They favored a military confrontation between the United States and Iran, and a prominent Iranian-American group in Washington that pushed back against war—and favored a diplomatic solution to the US-Iran standoff—was an obstacle.

Despite their efforts, for more than a year Trump was thwarted in delivering on his campaign promise to cancel the nuclear deal by the advice he received from his then-secretary of state, Rex Tillerson, and his then-national security adviser, Lt. Gen. H.R. McMaster, both of whom reminded him that Iran was not in violation of the agreement. And it appears that the Black Cube fishing expedition failed to provide any justification for breaking the agreement. But having replaced Tillerson and McMaster with two noted Iran hawks, Mike Pompeo and John Bolton, Trump finally made his move this week to cancel the deal. On Tuesday, he gave a speech at the White House that seemed intended to prepare the American public for a far greater confrontation with Iran. The speech was no doubt written with extensive input from Bolton, who has long promoted the idea of using military action against Iran to achieve regime change.

It seems clear that whoever hired Black Cube also favored the US’s withdrawal from the Iran deal. But we need to know more: if a foreign private intelligence agency was hired to help change a vital aspect of US foreign policy, with global consequences, it is a matter of urgent public interest to discover who ordered the operation and who paid for it, who else was targeted, and whether any foreign power had a part in it. Congress has a responsibility to investigate not only who commissioned Black Cube, but also whether the operation was tied to the White House. If the Trump administration was involved in a Nixonian campaign to justify its disastrous policy-making, we deserve to know.