Chad–Nigeria relations in the late 1970s, clashes occurred around Lake Chad, where both countries hoped to exploit oil reserves. Both also sought to defuse these confrontations, first by establishing joint patrols and a commission to demarcate the boundary across the lake more clearly. Then in the early 1980s, the low level of Lake Chad brought a series of tiny islands into view, leading to further disputes and disrupting long-standing informal trade networks. This relationship was also complicated by Nigeria's own instability in the north, generated by rising Islamic fundamentalism. Thousands of casualties occurred as the result of violent clashes in Nigeria throughout
Nigeria (), Niger (), Chad (), Cameroon (), and has a coastline of at least s. Nigeria lies between latitudes 4° and 14°N, and longitudes 2° and 15°E. The highest point in Nigeria is Chappal Waddi at . The main rivers are the Niger and the Benue, which converge and empty into the Niger Delta. This is one of the world's largest river deltas, and the location of a large area of Central African mangroves. Nigeria has a varied landscape. The far south is defined by its tropical rainforest climate, where annual rainfall is a year. In the southeast stands the