European rearmament is counted in platforms, ammunition, industrial capacity and deployable formations. Those are things that can be bought early and held. Military endurance also depends on inputs that cannot be bought early and held, and blood is the clearest of them. It is a biological resource drawn from a civilian donor population; a regulated medical product whose usable life is measured in days for some components and weeks for others; a laboratory output that must be tested and released before it exists in any legally usable sense; and a logistical flow in which temperature and traceability are conditions of validity rather than refinements of it. A force can therefore hold stocks and still lack a supply, because what it holds decays while it waits, and what replaces it has to be manufactured, in the strict sense of the word, out of people who volunteer. The question that matters for European defence planning is consequently not how much blood a country holds at a given moment, nor even how many donations it records in a year. It is whether the national systems that produce blood can raise and sustain the rate at which they convert eligible donors into released, deliverable, lawfully allocable product, for as long as a conflict lasts, while continuing to meet a civilian demand that does not pause. Finland and France answer that question in two different institutional registers, and the gap between what each publishes and what each withholds is itself part of the answer.