Russia used to be the Soviet Union. No one thought it would fall apart either. It too had a Constitution prohibiting secession.
When a group of people have interests that are so divergent that they cannot find any ground to co-exist that nation will not stand. It doesn't matter which one it is.
When a group of people have interests that are so divergent that they cannot find any ground to co-exist that nation will not stand. It doesn't matter which one it is.