Not every French ship needs to remain in the western Mediterranean. Submarines and heavy cruisers can support North Atlantic blockade patrols, adding hulls to the effort against German surface movements. The principal French battle force can remain in North Africa, where battleships and cruisers operate under friendly land-based air cover. Even if it could not defeat Italy alone, the damage it might inflict prevents the Italian navy from concentrating freely against either Allied fleet.
Chapter · 34:38-36:16
French cruisers, submarines, and shore aircraft widen the blockade
French submarines and heavy cruisers can reinforce Atlantic blockade duties while the main battle fleet contains Italy.