The Cold War, especially in the 1950s and 1960s, put a damper on the Esperanto movement as well, as there were fears on both sides that Esperanto could be used for enemy propaganda. However, the language experienced something of a renaissance in the 1970s and spread to new parts of the world, such as its veritable explosion in popularity in Iran in 1975. By 1991 there were enough African Esperantists to warrant a pan-African congress. The language continues to spread, although it is not officially recognised by any country, and is part of the state educational curriculum of only a few.