Subdivision a nation increases the risk of being bullied by the international community.  It strengthens organizations like the United Nations because it would make resistance more difficult. The tyranny of the majority on a national scale.  

I am not arguing for or against this.  I am just pointing out potential problems that I see. 

For every choice we make there are benefits and consequences.

Choose wisely... 

 You have a point. Had Ukraine remained part of the Soviet Union, the United States and NATO might not have intervened in its internal affairs, and Russia may not have been provoked to invade it. But perhaps they should not have given their nukes over to Russia.