In the history of Europe as I described it in my book LIBERAL QUICKSAND I assign an important place to the principle of National Self Determination (PNSD). It was invoked throughout recent history to justify the creation of new nations/states.
To a certain degree the principle is used ( but only sparsely) in theories of political philosophy.
And in International Law we only find an explicit confirmation of this right when the status of colonies is discussed (Declaration on the Granting of Independance to Colonial Countries and Peoples – Resolution 1514 xv – 1960).
Therefore, what seems central in history, in the past does not seem to have a place in the world of today ?