European rearmament is raising the value of industrial land that was designed, used and repeatedly modified for defence production long before the present expansion began. Munitions, explosives and propellant plants are hard to relocate. Their productive value lies not only in buildings and machinery but in safety distances, protected perimeters, utilities, environmental permits, explosives licences, specialist labour and settled logistics. Extending or reusing an existing site is therefore usually the faster and cheaper route to additional output. The same choice carries a particular execution risk. Contamination left by earlier decades of production can be legally attributable to one party, administratively enforceable against a second, economically borne by a third and technically uncharacterised until excavation begins. A site can consequently be owned, financed and authorised before anyone has shown that the ground will support the works on which new capacity depends. The relevant question is not the abstract size of Europe’s environmental liabilities, which no public record allows anyone to measure. It is narrower and more practical: when does the contamination of an established defence site become a variable in financing and readiness, and which legal and financial instruments decide who acts, who pays and who must prove that the land is fit for its new industrial use?