While the MPLA espoused multi-racial and cosmopolitan views, Mobutu was a black nationalist with strong ideals of African authenticity.  Starting in 1975, Zaire sent several battalions of regular soldiers as well as commando units into Angola, after unsupported FNLA guerillas proved ineffective.  Even with significant weapons provided by the US and other Western nations, the Zairians were decisively defeated by the MPLA and their Cuban allies. 