The German federal audit office, examining the Tiger attack helicopter, found that the benefits expected from developing and procuring the aircraft with France and Spain had been reduced by technical differences between the national versions, and that the acquisition cost of the 80 aircraft Germany finally bought — out of 212 originally planned — had risen by €630 million to €3.6 billion. Set against the other programmes examined here, that is neither the largest commitment nor the smallest. The Franco-Italian FREMM frigate programme cost about €6 billion on the figure used by the French National Assembly’s evaluation mission; the Netherlands committed €619,559,793 for 200 Boxer armoured vehicles inside a replacement project costed at €2,259.1 million; the United Kingdom carries a whole-life cost of £2,904 million for a single Typhoon radar programme. What the audit did not do is allocate the €630 million to the national variants, and no European document has done so since, for any programme. That is the structural constraint. A shared programme name, a multinational contract or a common prime contractor does not establish that participating armed forces possess the same military system, and the public record prices the consequence nowhere. The question that follows is not whether sovereignty should give way to standardisation. It is whether a sovereign deviation can be kept bounded across the equipment life cycle, and how a procurement authority would know before the answer is fixed.