Domino theories have been much in issue, and much in dispute, in the post-Second World War history of Southeast Asia. They seem decidedly applicable to the post-Second World War history of tropical Africa. As was well understood, there were in Africa various territorial differences of some magnitude. There were differences too between the policies of its different imperial powers and, indeed, between the policies of the same imperial power in different parts of Africa. But, aside from the partial exception of Egypt and the clear exception of Algeria, there were, in broad terms, three successive sequences to the independence of Africa outside the Union of South Africa, and domino theories were applicable to all three of them.

The first sequence extended from the independence of Libya in 1951, through the final withdrawal of British troops from Egypt in 1955, to independence for Morocco, Tunisia, and the Sudan in 1956. Algeria's exclusion from this first sequence precipitated one of the two colonial wars1 of the first two sequences; but, apart from Algeria, by the mid-1950s all of North Africa had as a consequence become independent. It was widely anticipated that if there were to be further chain reactions in the attainment of African independence, there would be upwards of at least half a dozen of them. There were in fact just two. The more extensive one (the second of the three sequences) involved the precipitate fall of a whole string of colonial regimes right across the middle of tropical Africa – thirty of them all told – in one quite unexpected collapse.