ABSTRACT
Citizenship practices have been thought the last bastion of national sovereignty. As international norms have aggressively invaded virtually every sinew of domestic governance, nationality law has remained largely immune to any acknowledged constraint from beyond. As a doctrinal matter, it has been allocated (in the characterization of a prominent international pronouncement on the question) to a “domain resérvé” in which states are free to rule according to their own preferences. But this regime is showing early signs of slippage, and is unlikely to persist into the future.
