Why reserve crews matter after the regular force absorbs the opening shock

Does a shortage of crews make a much larger naval reserve especially important?

Yes. Regular personnel may carry the opening weeks, but a long war needs trained reservists to expand the fleet and replace exhausted, wounded, or killed crew members.

A regular force is designed to respond quickly and absorb the first period of intense operations. If the conflict continues, fatigue and casualties erode that trained core even before new ships require crews. Reservists provide replacements, reinforcement, and institutional depth without waiting for civilians to be trained from the beginning during a crisis. Recent long wars demonstrate that states with usable reserve formations and personnel pools can sustain operations that a narrowly optimized standing force cannot.