Modern aircraft generations are usually defined through American criteria because the United States currently provides the benchmark air force, navy, and naval air arm. That comparison is practical and changes over time. Earlier eras used the Royal Navy, and before it French, Dutch, or Spanish naval practice, as the standard against which others were judged. A common yardstick does not mean that every developing force must reproduce the benchmark navy's exact requirements.
Notable Point · 34:16-34:49
Why benchmark forces shape aircraft comparisons
Aircraft-generation labels and capability comparisons follow the standards of the leading force of the era, which today means measuring naval aviation largely against the United States.