have desirable ecological effects such as the tree crops and the legumes, which help prevent the process of desertification. However, there is the enduring question of whether cash crops like cotton are more important than food plants like wheat and casava. This issue persists as studies cite that the famine is linked to the direct entitlement failure that affected people's access to food. Over-population Many of the world's countries, including many in Sub-saharan Africa, the Middle East and South East Asia, have seen a sharp rise in population since the end of the Cold War. The fear is that high population numbers are putting further strain on natural resources, food supplies, fuel supplies, employment, housing, etc.; in some of the less fortunate countries. The population of Chad has, for example, ultimately grown from 6,279,921 in 1993 to 10,329,208 in 2009, further straining its resources. Nigeria is witnessing a similar growth in population, strained resources and a possible over-population problem in the near future. The situation was most acute in northern, western and central Africa. Refugees from places like the Sudan have helped further strain the resources of neighbouring states like the Chad and Egypt. The nation is also host to roughly 255,000 refugees from Sudan's Darfur region, and about 77,000 refugees from the Central African Republic, whilst approximately 188,000 Chadians have been displaced by their own civil war and famines, have either fled to either the Sudan, the Niger or, more recently, Libya. Aid workers being driven off by kidnappers On 25 August a French aid worker was kidnapped in Chad. The kidnapping of foreigners along the Chad/Darfur border became more frequent in 2009. A French NGO worker was taken and then murdered on 29 October 2009, and an unidentified Red Cross worker was captured on 10 November 2009. Many NGOs and charities have begun to restrict the areas covered by their aid work in Niger, Chad, and Sudan due to the ever-present risk of bandits and kidnappers. The organisations are thus pulling out in fear of their workers' lives. Most international aid agencies have been withdrawing workers from some areas of the Sahel, due to the regional kidnapping crisis. Niger's government spokesman Mahamane Lawali Danda told the BBC that the pullout was a surprise to him since no one had told him or his government that Niger was on the list of dangerous 'kidnapper infested' pariah nations, along with