U.S. presidential candidate Joe Biden has expressed he’d be open to quickly re-entering the Joint Comprehensive Plan of Action (JCPOA) if Iran returns to full compliance. But his predecessor’s hardline policies would probably necessitate expanding the scope of negotiations with Tehran beyond the current deal, leading Iran to adopt an even harder position on its nuclear program. Biden criticized the Trump administration’s hawkish Iran policy and 2018 withdrawal from the nuclear deal in a Sept. 13 opinion piece, in which he wrote that returning to the JCPOA could be the start of broader diplomacy between Tehran and Washington. Simply re-entering the JCPOA, however, would be difficult for both Washington and Tehran, as the current U.S. sanctions architecture is now far more complex than it was when the deal was signed in 2015. ...