Scotland has been in political union with the rest of Great Britain for over 300 years but the desire for independence still exists among many.
Scotland has a strong and enduring independence movement which currently controls the local parliament and has put a referendum to that effect on the ballot. On September 18 the people of Scotland will vote on whether or not they think Scotland should be an independent country. Polling currently indicates the referendum will likely fail but has significant support.
If even after centuries a nation with a shared language and landmass is still seriously debating if it should actually be a single country, that should tell us something.
Getting peoples from different regions with different histories, languages, and/or faiths to believe they should be part of a single county is extremely difficult. That task is likely made even more difficult when the borders of the country were drawn haphazardly by a foreign colonial power.
Photo by Dave Conner under Creative Commons license