Iran’s President-elect Ebrahim Raisi attends a news conference in Tehran, Iran June 21, 2021. Majid Asgaripour/WANA (West Asia News Agency) via REUTERS As European and US diplomats voice their frustration with Iran’s new demands amid last-ditch efforts to revive the 2015 nuclear deal, experts say Tehran is demonstrating little interest in moderating its stance, undeterred by the threat of harsher economic sanctions should diplomacy fail. Indirect nuclear talks between Iran and the world powers, which entered their seventh round on Nov. 29 in Vienna, are verging on collapse as Tehran under recently-elected president Ebrahim Raisi has abandoned compromises achieved in...