The sentence that features an allusion is: “Young people behind the Iron Curtain would see Selma and eventually tear down that wall.”
This refers to two significant historical events: the Iron Curtain, which symbolizes the division between Eastern and Western Europe during the Cold War, and Selma, which is associated with the Civil Rights Movement in the United States. The mention of "tearing down that wall" also alludes to the fall of the Berlin Wall.