Land-based fighters can demonstrate presence, but they must return to distant bases for fuel, weapons, and reinforcement. Tankers can extend an aircraft's reach without solving the problem of rearming it close to the threatened area. A carrier moves air power, maintenance support, and resupply closer to where they are needed. It also lets a geographically large but thinly populated ally make a more credible contribution to collective defence rather than relying entirely on another power's forces.
Chapter · 5:17-9:18
A mobile airfield for large, sparsely populated states
Canada and Australia faced the same problem: defending immense spaces with dispersed populations and air bases far from the point of need.