What being prepared for war actually means

What wars offer examples of participants that were actually prepared?

Some Anglo-Dutch and Napoleonic wars followed deliberate rearmament, while the Six-Day War showed one side far better prepared; the practical standard is resilience and a high enough fighting-efficiency level to survive the opening phase.

The Second Anglo-Dutch War and parts of the Napoleonic cycle followed deliberate rearmament during periods of peace. The Six-Day War is offered as a case in which Israeli forces proved much better prepared than their opponents. Useful readiness means enough resilience to absorb the first blow and create time for full mobilization, rather than completion of every programme. In the estimate given here, the Royal Navy entered the Second World War less than thirty percent through a programme intended to reach roughly seventy percent readiness by 1942. Crews could remain efficient even while ships and force structure lagged, so personnel quality alone did not make the fleet fully prepared. This is a more practical standard than demanding one hundred percent readiness.