Why has north korea remained isolated and poor?

i thing that the best option is a.they feared it would cause a second economic collapse.

one of the most negatives aspects of the new deal was that it upset the balanced federal budget and led to a huge deficit for the nation while at the same time failed to end increasing unemployment. roosevelt's program, based on keynesian theories of economics, called for massive government spending to stimulate the economy. as he   failed to do this with large tax increases; large sums of money were borrowed to fund new deal programs. when the economy showed some improvement, roosevelt was concerned about inflation, and ordered cuts in government spending. unfortunately, he did so at a time when the new social security tax had cut people's disposable income. businesses were too afraid of spending, and the economy in 1937 was in worse shape than in 1929. at the end of that year, two million people were unemployed.

regarding the law, the 15th amendment was specifically designed thinking in the rights of black free men.

even though ratified on february 3, 1870, the promise of the 15th amendment would not be fully applied for a long time.poll taxes and literacy tests would allow southern states disenfranchise african americans. only in 1965 the voting rights for african americans would be actually able to vote in the south.

in 1965, president johnson signed the voting rights act, which aimed to overcome legal barriers that prevented african americans from voting as it was guaranteed by the 15th amendment to the u.s. constitution.