Greece is not major country of the Europe, but why its debt affects the market globally? The answer is in the high school history text book. World War I started off from Europe because of the conflict between European countries about the colonies. Then World War II started off because of the debt of the World War I. Do you get it? This is all about debt or money again. Greek debt is not dangerous at all, but how different countries react to it differently reflect the dangerousness.