Should President-elect Joe Biden return the United States to the 2015 multilateral Iran nuclear deal? Experts and former U.S. officials are publicly weighing in on the issue – both for and against – and to a degree not seen on other anticipated foreign-policy steps. As Mr. Biden and his national security team have spelled out recently, Step 1 of a Biden plan would be a return to the deal, from which President Donald Trump withdrew in 2018, in exchange for Iran’s return to compliance. Step 2 would be a return to negotiations to address both the original deal’s sunset clauses and other destabilizing Iranian activities beyond the nuclear program.