Answer:
The United States did not complain about the construction of the Berlin Wall in 1961 because it protected West Berlin from any attempts of the Soviet Union to conquer it.
Step-by-step explanation:
The Berlin Wall is conventionally considered the ultimate symbol of the Cold War because it was erected with the purpose of separating the areas of domination from the powers that then divided the world at that time: in this case the USSR, Union of Soviet Socialist Republics, and the western powers, led mainly by England and the United States. The United States did not complain about the construction of the Berlin Wall in 1961 because it protected West Berlin from any attempts by the Soviet Union to conquer it.