A force with only enough fighters, destroyers, and aircraft carriers for the expected demands depends on everything going according to plan. Extra military assets cannot simply be hired when circumstances change. An imagined rental-company call on behalf of the Ministry of Defence asks for fighter squadrons and a destroyer or two, exposing the problem with that assumption. Even if the equipment could be hired, crews would still have to be found. Those crews would need training to operate within the receiving country's systems, so access to equipment alone would leave a further capability gap.
Notable Point · 0:48-1:35
Why military capabilities cannot be hired at short notice
Fighters, destroyers, and aircraft carriers cannot simply be hired to cover a shortfall, and even hired equipment would need suitably trained crews.