"as if it were a once friendly fort that might now be manned by Arabs."
Probably a reference to a popular boys’ fantasy of serving in the French Foreign Legion. Established in 1831, the Légion étrangère was a special unit in the French army for foreign nationals who wished to serve, but always under French officers. Algeria was its base for the next 130 years, so although members of the Legion served across the globe, most popular depictions of its actions (from P.C. Wren’s 1924 novel Beau Geste, subsequently made into several movies, to the 1998 film Legionnaire starring Jean-Claude Van Damme) show its soldiers fighting Algerian Berbers, which resemble Arabs.