SOURCE: https://en.wikipedia.org/wiki/Death_to_America
A conference named “Long Live Death to America” held on November 3, 2015, at Tehran University explores historical reasons for chanting the slogan.
Following the fall of the pro-American Pahlavi dynasty in early 1979, Iranian protesters regularly shouted “Death to America” and “Death to the Shah” outside the U.S. embassy in Tehran, including the day the embassy was seized on November 4, 1979, which commenced the Iran hostage crisis.[20] Throughout the crisis, Iranians surrounding the embassy chanted “Death to America” and “Death to Carter.”[21] When Iran released the remaining 52 American hostages on January 20, 1981, they were led through a gauntlet of students forming parallel lines that shouted “Death to America” as they boarded the airplane that would fly them out of Tehran.[22] “Death to the Soviet Union” and “Death to England” also became popular. A similar slogan “Death to Israel” (Persian: مرگ بر اسرائیل) is also used, and regularly chanted in Iranian and Pakistani political rallies.[9] It is the best-known variation.[23] However, the slogan predates back to the 1950s when it was first used by North Korea during the Korean War (known in North Korea as the Fatherland Liberation War) and it is still in use to this day.[1]
