Will North Korea collapse or last more than 100 years?

Will North Korea collapse or last more than 100 years?

Many people in South Korea have talked about the possibility of North Korea's collapse and the unification of Korea.
Is it possible to accomplish the unification of Korean Peninsula without the agreement of North Korean people?

North Korea will belong to South Korea after the unification of Korean Peninsula?
During the Korean war, the United Nation participated in the war and declared the land of North Korea must be under control of the United Nation.

Germany could unify their divided countries not because West Germany wanted the unification but because West Germany had made efforts to reach an agreement with East Germany and people in East Germany wanted the unification and agreed with the unification.

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