Why older Harpoon missiles still have wartime value

Why should a navy retain older Harpoon missiles?

Many potential targets have limited missile defences, and finite interceptor stocks can leave even better-defended ships vulnerable to a later attack.

Harpoon's age does not make it useless against every ship. Many navies lack the defensive equipment needed to counter anti-ship missiles, with the gun-armed Irish patrol fleet used as an example. Even a well-defended ship has a finite interceptor magazine. In the illustrative exchange, twelve advanced attacking missiles draw twenty-four defensive missiles, leaving older Harpoons a better chance in a following attack. Cost and the volume of available missiles therefore matter alongside the capabilities of individual weapons.