Air attack is the carrier's primary threat, yet navies do not always mount every layer of close defence on the ship itself. Weapon debris on the flight deck can enter aircraft engines and cause serious damage. Cost, the assessed threat, and the desire to justify another escort can also shape the decision. Missiles carried by a dedicated escort may be more useful than a small battery on the carrier, so the choice depends on the defensive force available around the ship.
Notable Point · 8:17-9:49
Why carriers may shift close defence to escorts
Flight-deck debris and budget choices can push close-in weapons off the carrier, trading organic protection for another escort.