The significance of the lines from President Ronald Reagan's 1987 speech revolves around the call for increased freedom and the reunification of Berlin, which symbolized the ideological divide of the Cold War. Specifically, Reagan famously challenged Soviet leader Mikhail Gorbachev to "tear down this wall," referring to the Berlin Wall that had separated East and West Berlin since its construction in 1961.
This call was more than just a demand for the physical demolition of the wall; it represented a broader appeal for freedom and human rights in Eastern Europe and the end of oppressive communist regimes. It highlighted the tensions between the East and West during the Cold War and underscored the U.S. commitment to supporting democratic movements.
The correct interpretation is that Reagan was demanding that the Soviet Union open up Eastern Berlin to freedom and reunite the city, emphasizing a vision of a more united, free Europe, which contributed to the eventual fall of the Berlin Wall in 1989 and the collapse of the Soviet Union.