CANBERRA – One of the many things the world has learned from the Iran nuclear saga is that its leaders made a mistake, when negotiating the Nuclear Non-Proliferation Treaty (NPT) in the 1960s, in not doing anything to constrain uranium enrichment and plutonium reprocessing. This failure apparently stemmed from the belief – long since proven wrong, certainly in the case of uranium – that the only states ever likely to possess that technical capability already possessed nuclear weapons, or (like Germany) were totally committed never to acquire them.