The current issue of Lancet Infectious Disease has a news story on the continuing neglect of visceral leishmaniasis.
The author makes the point that war and civil unrest are major impediments to control of endemic communicable disease. This article uses the example of the political situation in Sudan hampering programs for treatment of leishmaniasis.
This is only one example of many, of course. Regional elimination of disease is impossible if even one country in an endemic area has an ineffective government program. An even better example is the onchocerciasis control program (OCP) in West Africa. The OCP was a major effort to eliminate onchoceriasis in West Africa in the 1970s-1990s. In many countries the OCP worked to control onchocerciasis and prevent river blindiness. However, despite international investment, aggressive vector control, and coordinated government/NGO treatment programs, the OCP failed to eliminate onchocerciasis from West Africa primarily due to the decades of conflict in Sierra Leone.