In the conventional view, the earliest preparations for war involve building a strong industrial base, reducing corruption, and securing alliances through cooperative foreign policy. The near-term preparations for war include diverting a fraction of total resources away from compounding growth and towards non-compounding defense manufacturing. A draft is something you do after the war starts.

The strategic idea is to remain in a pose of compounding growth as long as possible by avoiding war and war preparations until they're known to be absolutely necessary. Peacetime investments like scientific research build on themselves, while military spending sits in a depot until it's obsolete and then costs even more to safely dispose. The same goes for replacing the first two years of professional school with standing around in a big shed.

Sure, but you also don't keep 1.3 million firefighters idling in case of a really big fire.