4. Nigeria: Ranking 44th among 126 military forces across the world, the Nigerian Army turns out to be the fourth most-powerful military base in Africa. Guarding a population of more than 181 million civilians, the Nigerian army can boast of a labor force of 55,780,000 members with a total defense budget of more than $2.3 trillion. As the most powerful military in West Africa, the Nigerian Army has 105 total aircrafts and 38 helicopters.