With the increased mobility and interdependence brought on by globalisation, governments can no longer deal effectively with what were traditionally regarded as -domestic issues- unless they cooperate among themselves. International law may once have been a sort of inter-state law concerned mostly with relations between states, but it now looks increasingly inside state borders and has become, to a large degree, a trans-governmental law. While this creates significant challenges even for highly-unified -nation-states-, the challenges are even greater for federations in which powers have been...