ARTICLE 78
The conduct of relations with foreign countries is exclusively a function of the Commonwealth.
The States, in matters subject to their jurisdiction, may conclude treaties with foreign countries; such treaties require the assent of the Commonwealth.
Agreements with foreign countries regarding changes of national boundaries will be concluded by the Commonwealth with the consent of the State concerned. Changes of boundaries may be made only by authority of a national law, except in cases where a mere adjustment of the boundaries of uninhabited districts is in question.
To assure the representation of interests arising from the special economic relations of individual States to foreign countries or from their proximity to foreign countries, the Commonwealth determines the requisite arrangements and measures in agreement with the States concerned.