What was the meaning of the red scared during 1950s

A "Red Scare" is the promotion of a widespread fear of a potential rise of communism or anarchism by a society or state. ... The First Red Scare, which occurred immediately after World War I, revolved around a perceived threat from the American labor movement, anarchist revolution and political radicalism.

when the chinese communist party took power in 1949, it began to build new di and levees to hold the yellow and yangtze rivers back.