Two days after US-led negotiators missed their June 30 deadline for an agreement with Iran on its nuclear program, Yukiya Amano, director- general of the International Atomic Energy Agency (IAEA), arrived in Tehran. He had met with Iran’s leaders many times since assuming the helm of the UN nuclear watchdog in 2009, but this visit was particularly crucial. The US, as well as several European countries, had been resolute that unless Iran answered all outstanding IAEA concerns there would no deal.After meeting with Iranian President Hassan Rouhani and other senior officials on July 2, Amano announced a breakthrough. Iran would now fully cooperate with the IAEA. They had agreed on a “roadmap” with a timetable for Iran to provide answers to all questions about the possible military dimensions (PMD) of its nuclear program, and to implement the Additional Protocol allowing for inspections of nuclear sites in Iran. Amano declared that by mid-October he expected to receive the PMD information from Tehran, and would present to the IAEA board in December an “assessment” of the Iranian program.Amano’s quick trip was a welcome development for the American and other five countries’ representatives huddled with their Iranian counterparts in a Vienna hotel. It cleared a major barrier to finalizing the agreement, the Joint Comprehensive Plan of Action (JCPOA), that was announced nearly two weeks later on July 14.But the IAEA director’s turnabout was striking.What led Amano to relax his demands for immediate, full Iranian cooperation, and to give Iran an extension on complying with IAEA requests? Did any or all of the P5+1 countries pressure him? In meetings with US Senators on August 5, Amano was pressed on what some have called his side deal with Iran.“It was not a reassuring meeting,” remarked Senator Bob Corker, chairman of the Senate Foreign Relations Committee.Back in March, Amano said the IAEA “is not in a position to provide credible assurance about the absence of undeclared nuclear material and activities in Iran, and therefore to conclude that all nuclear material in Iran is in peaceful activities.” Emphasizing that point, Amano told Bloomberg news in April that “clarifying the possible military dimensions of Iran’s past is essential.”IAEA talks with Tehran over the years were held parallel to the P5+1 negotiations. At some point they would have to converge because, in the end, the IAEA would be tasked with monitoring the implementation of whatever agreement the P5+1 and Iran reached. US administration officials have stressed that sanctions relief depends on IAEA verification of Iran’s compliance with the Vienna agreement.The IAEA will be the “eyes and ears of the international community” in Iran, Amano told the BBC.Notwithstanding these high-stake expectations, the IAEA faces challenges in fulfilling its role. Current monitoring of Iran is already straining the agency’s financial and personnel resources. The IAEA has had anywhere from two to ten inspectors in Iran at any given time. More will be needed.Iran’s desire for sanctions relief may ensure that this time it will fully cooperate. But past experience suggests reasons for skepticism. Honoring the Additional Protocol will be a key test for Iran. Let’s recall that Iran first signed it in 2003. As Amano himself has noted, Iran ended compliance with that critical document in 2006.Agreeing to IAEA inspections of Iran’s 18 declared nuclear sites and to not obstruct requests to visit and examine any suspect site was significant and necessary.However, Amano told The Wall Street Journal during his Washington visit that Iran still is rebuffing IAEA requests to interview scientists and military officers associated with the nuclear program.The IAEA should try soon to visit one or more undeclared sites, even if processing a request takes up to 24 days, per the Vienna agreement. Making sure the inspections procedures really work is essential before approval is given to begin lifting sanctions on Iran. Still, Amano has admitted that full disclosure of the details of Iran’s nuclear program, past and present, will not be easy.“To come to a final broader conclusion that Iran’s nuclear program is fully peaceful” will be “a matter of years at least. Not months. Not weeks,” Amano said at a press conference at IAEA headquarters in June.The IAEA does not have the luxury of time. Amano has promised to decide by December whether Iran is complying with the JCPOA and can thus enjoy sanctions relief. “Amano could make or break the agreement with his choice of words,” observed The Guardian.He already gave the Iranians a lifeline, in tandem with the P5+1, by relenting on earlier demands that Iran come clean before a deal was signed. The six world powers that negotiated with Iran sit on the IAEA Board of Governors, which will vote on Amano’s assessment in December. As he showed on his July 2 visit to Iran, he is not likely to stand in the way of implementing the agreement.Announcing the agreement on July 14, US President Barack Obama said that it is based on verification, not trust. Yet how does one verify something without establishing a basis of trust that Iran will comply? And there needs to be faith in the IAEA’s capability to stay true to its mission as it monitors Iran’s implementation of the deal. Otherwise, it is doomed to fall short of its authors’ expectations.The writer is the American Jewish Committee’s director of media relations.