One of the particularities of Belgian federalism is the lack of an explicit and systematic enumeration of the duties of the federal state. The federal state is responsible for justice, public order, finance, social security, public health, foreign affairs and defence, as well as residual powers (powers not explicitly allocated to the communities and regions). Through the principle of “in foro interno, in foro externo” (power to regulate international cooperation for the matters assigned by the Constitution and special laws), the communities and regions have the possibility to conduct their own foreign policy.
The federal state retains control in the fields of foreign policy, defence, justice, finance, social security, health policy, internal affairs, and everything else not expressly assigned to the regions and communities. This does not prevent the communities and regions from pursuing their own foreign policy.