Nigeria, Dec. 17 -- States do not make important diplomatic decisions casually. Major postings, especially in volatile regions, are rarely accidental. They are signals, sometimes subtle, sometimes loud, about priorities, recalibration, and intent.

France's decision to post a new ambassador to Nigeria comes at such a moment.

Across the Sahel, France's traditional military footprint has collapsed. Mali, Burkina Faso, and Niger have either expelled or sidelined French forces. Bases once described as "stabilizing" have closed. A strategy once anchored in hard power has reached its limit.

But power does not vanish. It adapts.

What follows the loss of military access is often a shift in method rather than a withdrawal of interest. Influence...