There is little interest in unification among young people in South Korea  There is one very obvious historical example which speaks to attempts to unite Korea by force: the 1950-53 war. It seems unlikely that even the most ardent supporter of reunification south of the border would be keen to repeat that fiasco which had at least 910,000 battle deaths and total death toll up to 3.5million. [1]  In addition, the younger generations have much less interest in the proposal than their parents and grandparents did.  As a result the grand coalition would run the very real risk of one of the component parts actively opposed to the proposal and the other half at the very least unhappy about it.  The assumption that the North Korean army will simply roll over or melt away is reminiscent of the ideas about swift victories in Iraq and Afghanistan and so it seems unlikely that the US public would be too keen to sign up for a second Korean War.  Ultimately to work this proposal needs the support of the peoples of North and South Korea as well as those of, at least, the US and China. There is precious little evidence that any of those things are true.  [1] ‘Inter-State War Data’, Correlates of War v.4.0, 1816-2007 , ‘Korean War’, Death Tolls for the Major Wars and Atrocities of the Twentieth Century