1. Permanent population
2. Defined territory, (1969 North Sea Continental shelf)
3. Effective government: In Military and  Paramilitary Activities in and against Nicaragua ICJ 1986
4. Capacity to enter into foreign relations

• Political union with one or another State to form a new State.
• Political union is similar, but not identical, with the incorporation of one State by another State.
• Incorporation is usually consensual, and in this regard it is to be distinguished from annexation, usually (but not invariably) a unilateral act of seizure of territory that is later legitimated by recognition by other States.

• The first is dissolution: the existing State disappears, and new States succeed to its rights and obligations but not to its personality.
• The concept of continuing State’ invoked by the FRY (federal republic of Yugoslavia is important, as a continuing State retains the international personality of the original State: it is the same legal person. and need not re-apply for membership in international organizations, nor re-accede to treaties. es. The continuing State would also, in principle, assume the public debts of the disintegrating State.