I think both world wars found most countries unprepared. Some like Germany and Britain quickly realized the secrets to win the war and were advantageous. After the second world war, there was a period of transition marked by the cold war era. The cold war not only brought tension but also had many advantages.
After the colonial governments vacated office, the incoming African leadership did everything to show that they would exercise Justice and never rely on the whites for any aid. So they established manufacturing, processing, and assembling industries, some of which thrived but most succumbed due to inadequate funding and lack of skilled labor.