French colonial governance fragmented the Maghreb across different ministries. [causal]
At the top, Algeria — since it had been annexed as an integral part of France — was governed through the French Ministry of the Interior. This was in sharp contrast to its closely related Maghreb neighbours, over whom France established only “protectorates” during the nineteenth century and which were consequently dealt with by the Ministry of Foreign Affairs. Thus it would always prove difficult to formulate any co-ordinated policy for the Maghreb as a whole, and in fact such disparate territories as French West Africa and Indo-China came to have more homogeneous links through both being subordinated to the same Ministry of the Colonies.
Horne, Alistair, A Savage War of Peace- Alge…, loc. 90