Two Excellent Books on Secession:

For readers interested in the normative arguments for and against a right to secession, I recommend Allen Buchanan's 1991 book Secession: the Morality of Political Divorce, and Christopher Wellman's more recent A Theory of Secession. Unlike me, Buchanan advocates a presumption in favor of maintaining existing states, though a more limited one than under current international law. Wellman, by contrast, defends the view that any group should have the right to secede so long as it meets certain minimal criteria. He contends that a broad right of secession is a logical implication of the right to political self-determination. Both books are outstanding, and well worth your time if you are interested in these issues.

And if you are a Penn or George Mason student, you may be interested to know that I have a unit on the pros and cons of secession in my seminar on Federalism (scroll down for description). I didn't expect the issue to be quite as topical as it has become over the last few days as a result of the tragic events in Georgia.