What does Iran's latest missile test mean for the nuclear deal?

Iran on Wednesday confirmed reports that it had tested a medium-range ballistic missile over the weekend, launching it 630 miles before it exploded.

Iran’s ballistic-missile program, which it claims includes rockets that can hit Israel and US bases in the Mideast, has long drawn the ire of Western officials. Nikki Haley, US ambassador to the United Nations, called the test “unacceptable.” It comes at a time when President Trump and members of his administration are considering scrapping the 2015 Iran nuclear deal, officially known as the Joint Comprehensive Plan of Action (JCPOA).

Sunday’s test may have gone against the spirit of the deal, which was heralded as a major step toward peace in the Middle East, and UN Resolution 2231, which endorsed it. But it didn’t violate the letter of either document, and nonproliferation experts have cautioned that punishing Iran excessively could imperil the agreement.

“Security Council Resolution 2231, which endorsed the JCPOA, ‘calls upon’ Iran not to undertake until 2023 any activity related to ballistic missiles ‘designed to be capable of delivering nuclear weapons,’ the International Crisis Group reported last month. “However, the language is non-binding, and lack of an internationally-agreed definition of nuclear-capable missiles invites diverging views on the Iranian program.”

Despite its lack of teeth, analysts skeptical that Iran would agree to anything more stringent have regarded the deal as a step forward in reigning in Iran's missile activities.

“Ballistic missiles are central to Iran’s deterrence posture and will remain so for the foreseeable future," Michael Elleman, a former Lockheed Martin missile scientist, testified before a Senate committee in May. "Given this importance, Iran will not surrender its current systems, except, possibly, under the direst of circumstances.”

Under the deal, Iran did make concessions on its nuclear arsenal.

“The nuclear deal removed the existential threat of an Iranian nuclear weapon, and took the Iranian nuclear program off the daunting array of policy challenges that the US is facing,” Kelsey Davenport, a nonproliferation expert at the Washington-based Arms Control Association (ACA), told The Christian Science Monitor last month.

But other aggressive acts – including support of Houthi rebels in Yemen and the ballistic missile program – continue. Although the US maintains sanctions to punish these activities, some members of the Trump administration see the repeal of the nuclear deal as essential to stopping the regime’s other excesses; Trump's national security advisor, Michael Flynn, has called for “regime change” in the country.

Short of that extreme measure, Ms. Davenport said that excessive punishment for other Iranian actions – like the missile tests – could pressure the regime to a point where it abandons the deal. “They could provoke Iran to take a retaliatory move and create an escalatory spiral that eventually causes the deal to fold,” she told the Monitor.

With the first Iranian launch of his presidency, Trump now needs to decide whether he really wants to pursue that course of action.

This report contains material from Reuters and the Associated Press.