History
The Doctrine of State Succession in International Law
Quick fact
There is no single global rule for state succession: the 1978 and 1983 Vienna Conventions exist, but they have few ratifications and are widely seen as reflecting the interests of the states that drafted them, leaving much of the law to custom and practice.
Why this is interesting
When the Soviet Union dissolved in 1991, its place in the UN was quietly taken by Russia—but what happened to all of its treaties, debts, and membership obligations? The answer lies in a surprisingly murky area of international law: state succession.