It's a pretty good opportunity to verify the effectiveness of the 'spill over effect' or ‘functionalist theory’ from the Korean case. Economic integration slowly absorbed into political and security integrations. In the late 1980s, Germany was well prepared for their unification. However, situation is different for the two Koreas. They are not ready! The problems are caused from not only North Korean situations, but also South Korean political/economic affairs.
Most of the North Koreans are poor and its territories are wasted. It will probably take several decades to reconstruct the whole infrastructures for stable economies. South Korea has the world 11th largest economy; however, it will cost much more efforts to recover North Korean economy. IMF financial crisis in 1997 proved the severity of South Korea’s bubble economy. South Korea overcame successfully that crisis; however, the weak financial infra will result in a more disastrous outcome in the future. Still, South Korean economy is instable. Many experts used to saying Kaesong Industrial Complex (KIC) as a blueprint for integration of the two Korea. However, it is simply a symbolic in its size and investment rather than substantial. Unification of Germany was possible because of the thorough preparation of West Germany from establishing the basic infrastructure to the complex industries.
Political situations are more vulnerable than economies. South Korea is incompetent to play a leadership role to accommodate the impoverished North Koreans. Of course, South Korea is continuously developing its stable democracy after the first civilian government took office in 1987. However, its politics showed inconsistent and even severely corrupted. To be successful the reunification, South Korean political leaders should establish ‘norms’ to promote stable democracy. But, they lost their political trust. For example, South Korean President Roh, Moo-huyn elected as president through anti-Americanism. Still, many South Koreans remember the two middle school girls who killed by the USFK armored vehicle which make Roh successful in presidential election. After he became a president, Roh changed his attitude toward pro-American without considering the voters. Elite politicians also used to shift their political colors so frequently according to the situations. If South Koreans cannot give beliefs to North Korea, political integration is impossible. Social norms to construct a unified state are needed to prevent the political disorder.
Without the thorough studies and preparations, reunification would harmful to both Koreas.