When the Iranian nuclear agreement was reached in 2015 there was a hope — and it was just a hope — that the deal would lead to a more moderate Iran.As tough sanctions were lifted, Iran received billions of dollars in oil revenues that had been blocked. The country's international isolation eased, raising the possibility that Iran's friction with the U.S. and some Arab states might give way to greater engagement, at least in some areas.No one is talking like that now."I believe President Obama's flawed nuclear deal was a gamble, a gamble that Iran would choose to become a responsible actor," California Republican Ed Royce, the chairman of the House Foreign Affairs Committee, said at a hearing Wednesday. "The Tehran regime clearly still sees itself as a movement, one that uses ideology and violence to destabilize its neighbors."But you don't need a critic of the Iran nuclear deal to get an earful about Iran's aggressive behavior.Supporters of the nuclear deal offer similar complaints — beginning with Iran's ongoing ballistic missile tests. These missiles could potentially deliver a nuclear warhead, but they're not covered by the nuclear deal."The missile tests are very troubling, and particularly because they are done by the radicals in the most provocative manner possible," said Abbas Milani, the head of Iranian studies at Stanford University.U.S. allies, international inspectors and the Trump administration itself have all said Iran is in compliance with the nuclear agreement. But when it comes to everything that's not covered by the nuclear deal — including missile testing — Iran often remains at odds with the U.S.President Trump says the Iran nuclear agreement is an "embarrassment" and that he may declare Iran in violation. The White House says this week, he will announce his position on the deal — which the administration is required to do every 90 days — as well as his broader Iran policy.Milani supports the nuclear deal but is critical of Iran on many other fronts — like in Syria, where Iranian fighters have helped ensure the survival of President Bashar Assad, who appears to be in his strongest position in years."I think Syria is a fairly foregone conclusion," Milani said. "I don't think there's much the world can do to change the outcome of this now-ravaged country."And in Iraq, where the U.S. has been fighting for more than a decade in support of the government, Milani now believes that "Iran will have a virtual open hand to increase its influence."Iran also supports a host of radical groups, including Hezbollah in Lebanon, Hamas in the Palestinian territories and Houthi rebels in Yemen.But all this activity falls outside the limited scope of the nuclear deal.Iran, meanwhile, does not agree that it is the cause of the region's turmoil.Writing in The Atlantic, Iran's foreign minister, Javad Zarif, argues, "The evidence for 'bad behavior' by Iran is nonexistent. Iranian 'aggression' is a myth, easily perpetuated by those willing to spend their dollars on American military equipment and public-relations firms, and by those promising to protect American interests rather than those of their own people. In the end, they serve neither."Alireza Nader of the Rand Corp. advocates a two-track policy in dealing with Iran."It makes perfect sense to keep the nuclear agreement and push back against Iran in other ways," he said. "Iran is both susceptible to pressure and incentives."He said the U.S. could use the carrot — engaging Iran over a shared opposition to the Islamic State — and the stick, a threat of new, nonnuclear sanctions.Ali Vaez of the International Crisis Group notes that many Iranian policies, including strong support for Syria, date to long before the nuclear deal."I don't see any significant change in Iran's behavior before or after the nuclear deal," Vaez said.He says U.S. decertification of the nuclear accord could easily backfire."I'm afraid by undermining the nuclear agreement, the administration could usher in what it says it's trying to prevent, which is greater Iranian assertiveness," Vaez said. Trump says Iran gained much more in sanctions relief and business deals than it gave up with its scaled-back nuclear program. He insists he'll put more pressure on Iran, though it's not clear what action he might take or whether Congress will impose additional sanctions.Meanwhile, Royce, the Republican congressman, cautions against scrapping the agreement."As flawed as the deal is, I believe we must now enforce the hell out of it," Royce said at Wednesday's hearing.Greg Myre is a national security correspondent. Follow him @gregmyre1. Copyright 2017 NPR. To see more, visit http://www.npr.org/.