Rivalry and disunity within developing regions

Lack of sense of community and solidarity within developing countries
Tradition-bound rivalries
In the Arab world, on the Indian subcontinent, in Africa and in Latin America, solidarity is lacking and developmental rates are slowed by intra-regional rivalries and misunderstandings. In South America rivalry between Argentina and Brazil is notable, and there is a sense of difference between Andean countries and other OAS members. In Southeast Asia, ASEAN members and non-members cannot unify on a regional basis to further development. In Southern Africa, the region is neglected while civil wars and international hostilities continue. The lack of, or a weak sense of regional identity afflicts the Caribbean, the less developed countries of the Mediterranean basin including insufficiently developed parts of Europe, and it afflicts central Africa.
Austria and Turkey, North Korea and Japan, the Netherlands and Belgium are all examples of near neighbours who have mutual differences. What is it about the "developing country" label that allows the most simplistic slurs to find their way into acceptance ? The perception that a developing country is part of a homogenous region is a convenience of international organizations who for developmental aid purposes are largely responsible for introducing the regional concept, at least in the developmental perspective. The regional concept has more reality in international funding budgets than anywhere on the ground.
(C) Cross-sectoral problems