Iran fired missiles at targets in Israel and Gulf Arab states on Sunday after vowing massive retaliation for the killing of Supreme Leader Ayatollah Ali Khamenei by the United States and Israel, prompting US President Donald Trump to threaten Tehran against further escalation. Iran acknowledged Khamenei's death in the joint Israeli-American airstrike Saturday at his Tehran office hours, which has thrown the future of the Islamic Republic into question and raised the risk of regional instability. The 86-year-old's death at his office "showed that he consistently stood among the people and at the forefront of his responsibilities, confronting what officials call global arrogance," Iranian state TV said. Trump said the killing of Khamenei gave Iranians their "greatest chance" to "take back" their country. "Khamenei, one of the most evil people in History, is dead," Trump wrote in a social media post. Iran's Cabinet vowed that this "great crime will never go unanswered", and the ...