The imbalance is regularly restated: the continent that accounts for most of the items on the Council's agenda holds no permanent seat on it.
The veto, the main sticking point
Enlargement without equal rights would formalise a hierarchy among permanent members. Conversely, multiplying the number of veto holders risks paralysing the body still further.
Choosing who would hold the seats requires a continental agreement on criteria (demographic weight, contribution to peacekeeping operations, regional balance) that no institution has yet set down in writing.
Any change to the Council's composition finally requires amending the Charter, subject to ratification. It is that clause, more than substantive disagreement, that explains why the file has stalled for decades.