(i) Geography: Nigeria is bordered on three sides (north, west, North east and east) by Niger, Chad, Cameroon and Benin Republic. Because of this physical proximity, she is able to relate with them amicably.
(ii) Culture: The neighboring countries share the same culture and ethnicity with some States in Nigeria. The colonial artificial boundaries in many instances cut villages into two. Nevertheless, official languages differ i.e. English for Nigeria and French for Niger, Chad, Benin Republic excerpt Cameroon which is bilingual.
(iii) Economic: Trade activities with her neighbors strengthened their economic ties.
(iv) Security: Instability in all the neighboring countries has had repercussions Nigeria and vice versa.
(v) Common membership of international organizations
(vi) Natural disasters like flood, drought, etc.
(viii) Cross-border crimes
(ix) Bilateral agreements