Samsung has taken the technological lead and threatens to send the only two remaining American icons down into irrelevance, Motorola and Apple. This is a threat to the American economy and American technological dominance. Japan feels the same way, overtaken by its former colony it used to look down at.
So, by provoking a war and destroying South Korea they expect to create a vacuum they are ready to fill up. They will destroy South Korea while pretending to protect it. The formula is simply, provoke the North into attacking the South, hopefully using nuclear and chemical weapons then retaliate against the North, who will take all the blame. Leave it to China to rebuilt the North, America will rebuilt the South. They will be heroes, while Samsung and other Korean multinational will exist no more. South Koreans will be so gratefull with the Americans while ignoring that this war was designed to happen that way so that the west continue dominance can be guarantee and will not be threaten in any front.
