How did the red scare contribute to america's policy of isolationism in the 1920s?

the right answer for the question that is being asked and shown above is that: "their policy of "divide and rule" pitted political groups against each other to keep any one group from becoming too powerful.  " the  participant in european imperialism is being described below is that  their policy of "divide and rule" pitted political groups against each other to keep any one group from becoming too powerful. 

a phrase from a poem by ralph waldo emerson about the battle of lexington and concord. emerson's words read, “here once the embattled farmers stood / and fired the shot heard round the world.”