For Subscribers Los Angeles Times (TNS) Share One of Donald J. Trump’s greatest blunders as president was to repudiate the 2015 international agreement in which Iran accepted significant limitations on its nuclear program — restrictions designed to prevent it from developing nuclear weapons. Rather than pressuring Iran to accede to tougher limits, as the former president hoped, the decision to abandon the deal in 2018 and reimpose economic sanctions gave the Islamic Republic an excuse to begin openly violating the agreement. During last year’s campaign, Joe Biden promised that the United States would rejoin the agreement — known as the Joint Comprehensive Plan of Action — if Iran returned to strict compliance.