A German component supplier that decides to serve the defence market faces an interval with a characteristic shape. The production equipment has to be specified, ordered, paid for and brought into use; the base materials have to be qualified; the first articles have to be approved; and only then does series production begin to generate receipts. The equipment invoice falls due at the start of that interval and the revenue arrives at the end of it. Any financing instrument offered for defence-industrial expansion has to be tested against that shape, because an instrument that delivers value after the interval has closed does not solve the problem the supplier actually has. Accelerated tax depreciation is one of the instruments that has to be tested that way. Depreciation does not pay an invoice. It changes the amount and the timing of a tax payment, and it does so only for a business that has a tax payment to change. The relevant question is therefore not whether the German regime is favourable in the abstract, but under what conditions a corporate supplier can convert an accelerated deduction into cash it can spend before defence receipts arrive, and under what conditions the same deduction remains a tax attribute whose value lies in a future it may not reach. That question has a determinate answer, and it is not the one that the generosity of the headline rates suggests.