How did roosevelt strike a balance between isolationism and intervention in the 1930s?

the answer here would be

in the 1950s, country music came into its own before rock-n-roll took off in the 60s while jazz and classical music continued to innovate

i think it’s a i hope that right : )

john maynrd keynes developed new economic respose to the                           ( b. great depression if the 1930's)