One carrier gives status; three create capability

A single carrier is useful only when not refitting; two offer availability, while three begin to create a continuously usable capability. Air groups, escorts, and amphibious substitutes must also exist or the hull count exaggerates real power. This constraint shapes the carrier forces of Britain, France, Italy, Japan, China, and the United States in different ways. Sending a scarce carrier through Suez or Panama, or committing it to one crisis, removes it from every other demand and can leave the home region without the capability politicians assumed they possessed.