AUKUS is something of a phenomenon. The bombshell announcement at 7am on September 15, 2021, must rank as one of the most spectacular policy coups in Australia’s history. Though details were scarce, it was immediately and almost universally acclaimed as a triumph. Internationally, too, it has been a sensation, seen as transforming the Asian strategic balance and reshaping the global order. All this has given AUKUS an aura of inevitability. It feels too big and too bold to fail.

Yet doubts are growing. The more we learn about AUKUS, the more pressing the questions about it become. There are some obvious concerns about the astonishing cost, the environmental risks and the nuclear proliferation consequences. And there are more fundamental questions about whether we need nuclear-­powered submarines at all, whether the plan to get them could possibly work, and whether the wider strategic consequences will make us less rather than more secure.