{shortcode-62544e72d05ca694beb70c1ec4d35ffd066cefe7}Several Harvard social science professors criticized President Donald Trump’s withdrawal from the Iran nuclear deal, saying it will hurt America’s global credibility and could speed Iran’s progress toward obtaining a nuclear weapon.

The Iran Nuclear Deal—officially called the Joint Comprehensive Plan of Action—was negotiated under the Obama administration in 2015 to prevent Iran from building a nuclear bomb in the next 10 years. Under the plan, the United States and the European Union revoked economic sanctions on Iran’s oil and gas industries and provided other economic incentives. In return, Iran reduced its stores of enriched uranium, decreased its number of active nuclear reactors, and submitted to regular checks of its nuclear facilities by international monitors.

The Belfer Center for Science and International Affairs released a collection of statements from fellows and affiliates expressing their individual opinions on Trump’s decision to pull out of the deal and reinstate economic sanctions.

Many of the scholars are part of the Belfer Center’s “Iran Project," which connects Harvard and Iranian scholars to increase understanding of contemporary Iranian affairs. Though they agreed that the nuclear deal was flawed, many said the United States's exit won’t fix its problems.

Professor William H. Tobey wrote in a statement that if Trump’s main objections to the deal were its failure to compel total nonproliferation of nuclear weapons and its relatively short duration, then reinstating sanctions and giving Iran a window to reinstate their nuclear program only exacerbates those problems.

Kennedy School fellow Nawaf E. Obaid disagreed, however, calling the reversal “a much-needed move to correct a historically catastrophic policy by the Obama administration.”

Some professors said they worried that leaving the deal will make America a less effective negotiator and thus a less significant global power.

“If the United States can’t signal that it is committed to deals that it makes, then the value of diplomacy in negotiation is undermined, and other countries won’t negotiate with the United States.” Iran Project Director Payam Mohseni said.

“Trump is accelerating the retreat of America’s singular global leadership role,” R. Nicholas Burns, Kennedy School professor and former Under Secretary of State for Political Affairs wrote in a statement.

Government Professor Harvey C. Mansfield disagreed.

“This repeal puts pressure on our allies and on Iran to make this happen,” Mansfield wrote in an email, referring to calls for renegotiating the Iran deal. “And with a Europe made more active by American prodding, America will be stronger too.”

Some said the move may disillusion young, previously America-friendly Iranians and may empower conservative “hardliners”—supporters of Ayatollah Khameini—who initially opposed the deal.

The decision to withdraw will be “the first major bitter experience” with the West for Iran’s youth, Mohseni said. Mohseni, Burns, and Kennedy School Professor Matthew Bunn all warned that “hardliners” may now seek to discard the deal and pursue nuclearization.

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