The borders on the African continent are usually described as arbitrary since the postcolonial states largely inherited the lines which the European powers had drawn without any consideration for the situation on the ground as they scrambled for colonial possessions. Yet, after the former colonies became independent, the continent experienced only very few changes of its political borders. Charles G. Thomas’ and Toyin Falola’s monograph deals with this phenomenon by exploring the history of “Secession and Separatist Conflicts in Postcolonial Africa”. The terms “Secession” and “Separatist Conflicts” in the book title refer to an analytical distinction of the authors. While “secessionism” refers to the removal of a territory from the “host state” and the creation of a new independent state, “separatism” is a broader term that also includes demands for autonomy or comparable goals (pp. 8–9).
Based on this distinction, the study systematically examines six case studies, covering the period from the 1960s to the present day. In doing so, the authors mainly draw on secondary literature and published documents, whereas no archival research was conducted for the study. Unfortunately, even among the literature consulted, many relevant titles are missing in the bibliography, including important publications on the history of Africa’s postcolonial borders. Similarly, the literature consulted for the selected case studies is limited. For example, the chapter on the secession of Katanga mainly refers to older studies and political memoirs but overlooks more recent publications on the Congo Crisis. Hence, the reader can expect neither new findings on the explored conflicts nor an in-depth engagement with past research on the subject. However, this is not the purpose of the book. Rather, the authors aim to compare different kinds of separatist conflicts and analyse the changing form of separatism in Africa since the era of decolonization.
Falola and Thomas begin with the “Civil Secessions” that characterized the 1960s, defined by the authors as those cases where a region with an existing administration attempted to secede from a newly independent state. These secessions followed the model of the former colonies which recently had asserted their self-determination against the European colonial powers. The first such attempt, the secession of Katanga from the former Belgian Congo (1960–63), was ended when the United Nations, beginning in 1961, took military action against the secessionist movement and thereby set a precedent in African politics. Shortly after the failure of the Katanga secession, the Organisation of African Unity was founded, and its charter strongly endorsed the territorial integrity of its member states. When Biafra attempted to secede from Nigeria in the late 1960s, the anti-secessionist consensus on the African continent manifested itself in the overwhelming support for Nigeria’s strategy to militarily defeat the separatist region.
When the “Civil Secessions” failed in the 1960s, the secessionist wars in Eritrea and South Sudan analysed in the second part of the book were already under way, and after decades of struggle, they both ended with the creation of a new state, Eritrea in 1993 and South Sudan in 2011 – the only successful secessions on the African continent until today. The “Long Wars”, as the authors call these case studies, followed a different model of decolonization: the global liberation struggles in China, Vietnam, and Algeria. Ultimately, they succeeded and found international recognition, not least because the governments of the host states agreed to the secession – in Ethiopia because of a regime change in Addis Ababa after the end of the civil war in 1991, in Sudan because of the increasing international pressure on the regime in the north.
The third part deals with the “New Wave of Secessions” after the Cold War. With the end of the East-West rivalry, opportunities for African states to receive military aid from one of the superpowers dwindled – a development that already was crucial for the outcome of the Long Wars discussed in the previous part. Furthermore, after the disintegration of the Soviet Union and Yugoslavia, international acceptance of secessionism and ethnicity as a basis for statehood was rising. Especially the United States expected African governments to initiate reforms that considered the demands of subnational groups while separatist movements saw new openings to pursue their goals.
Nonetheless, secessionist demands faced strong opposition in the African context, as demonstrated by the case of Somaliland, whose declaration of independence in 1991 found no international recognition even though it de facto acts like an independent state and cultivates pragmatic relations with its neighbours. However, unlike in the cases of Eritrea and South Sudan, the Somali government in Mogadishu never agreed to the independence of its northern region, thereby impeding the chances of Somaliland for being accepted as a de jure souverain state. Separatist demands for less than full independence, though, were more likely to succeed after the Cold War. This is demonstrated by the authors through an exploration of the separatist struggle of the Kel Tamasheq (Tuareg) in Mali and Niger, where the violent conflicts that had erupted in the beginning of the 1990s ended in the second half of the decade with peace agreements providing autonomy for the Kel Tamasheq in Mali and the attainment of political concessions from the central government in Niger.
The peace was short-lived, as outlined in the conclusion of the book. Violence re-erupted once again in both states from 2007 to 2009 and in Mali in 2012. In the second case, the ethno-nationalist Kel Tamasheq fought together with radical Islamist groups, but the alliance did not last long and the Kel Tamasheq eventually re-aligned with the Malian state, which received considerable international support. This development points to another discontinuity the authors discuss at the end of the book: In the context of the global War on Terror, African states could again count on military support from the United States by casting themselves as “the bulwark against the new wave of Islamist groups that were emerging across the continent” (p. 284). Consequently, the opportunities for separatist groups that had emerged after the end of the Cold War diminished again in a post-9/11 world.
Observations on such changes are probably the biggest strength and most important contribution of the book to the history of the African territorial regime. While existing studies tend to emphasize the continuity of the African anti-secessionist consensus, Thomas and Falola identify several waves of secessions and discuss how they were shaped by the changing international context. In addition, the analytical distinction between “separatism” and “secession” as well as the comparisons between different kinds of conflicts introduced by the authors offer promising perspectives on the changing opportunities of subnational groups in Africa.
Still, some aspects of the proposed periodization are contestable. For example, while the authors rightly point out that the suppression of the Katanga secession set an important precedent, they overstress their argument. For them, “the UN charter specifically stated that it recognized and supported the self-determination of peoples”, while “there was at the time no specific mention that the already determined (and possibly illegitimate) political boundaries that had been in place since the Berlin Conference of 1885 were necessarily those of postcolonial Africa” (p. 27). Thus, the proponents of the civil secessions had reason to believe that their state “would be granted the same legitimacy as its previous host state” (p. 34). However, Article 2(4) of the UN charter explicitly states, “All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state”. And the First Conference of Independent African States in Accra, Ghana, in 1958 once again endorsed the territorial integrity of the postcolonial states on the continent. Consequently, when Katanga announced its independence in July 1960, anticolonial African state leaders like the Ghanian president Kwame Nkrumah promptly condemned the secession and blamed the development on Belgium, whose troops supported the secessionist province.
These imprecisions notwithstanding, Thomas’ and Falola’s work is an important contribution to the history of secessionism. Details of their periodization can and should be critically discussed, but altogether, they provide a convincing interpretation of the changing fates of separatist and secessionist movements in postcolonial Africa. Any future historical narrative will profit from engaging with this study.
 The book is available through open access: https://press.ucalgary.ca/books/9781773851266/ (19.01.2022).
 For example Jeffrey Herbst, The Creation and Maintenance of National Boundaries in Africa, in: International Organization 43 (1989), pp. 673–692, as well as the other publications on the subject quoted below.
 For example Lise A. Namikas, Battleground Africa: The Congo Crisis, 1960–1965, Washington 2012, as well as the other publication on the subject quoted below.
 For example Dirdeiry M. Ahmed, Boundaries and Secession in Africa and International Law: Challenging Uti Possidetis, Cambridge 2015, here p. 128.
 Crawford Young, Self-Determination, Territorial Integrity, and the African State System, in: Francis M. Deng / I. William Zartman (eds.), Conflict Resolution in Africa, Washington 1991, pp. 320–346, here p. 327.
 Ebere Nwaubani, Eisenhower, Nkrumah and the Congo Crisis, in: Journal of Contemporary History 36 (2001), pp. 599–622, here p. 613.