Why Cunningham attacked without waiting for Eagle

Why not postpone Taranto until HMS Eagle or more forces were available?

The attack had already been delayed, and Cunningham wanted to strike the concentrated fleet before it dispersed or intervened more strongly around Greece.

Taranto was an opportunity that could disappear if Cunningham waited for a perfect force. The original 21 October date had already slipped after a fire aboard Illustrious, and Eagle's readiness remained uncertain. British planners wanted to hit while the Italian battle fleet was still gathered and before it could interfere more heavily with the war around Greece. Worsening Mediterranean weather mattered, but postponement also meant waiting for the next full-moon window needed for the night attack. The decision demonstrates the difference between maximizing a hypothetical force and using the ships and aircraft available inside a narrowing operational window.