When the Soviet Union CCCP disbanded, and Ukraine became independent, it had a massive nuclear arsenal. The U.S. persuaded Ukraine to get rid of all their nuclear weapons in exchange for U.S. assurance that they would protect Ukraine against Russia. Here's an article on that:
A review of Mariana Budjeryn, “Inheriting the Bomb: The Collapse of the USSR and the Nuclear Disarmament of Ukraine” (Johns Hopkins University Press, 2022).
www.lawfaremedia.org
In the article, it quotes Clinton, "Even President Bill Clinton in a recent interview expressed regret for having pressured Ukraine to disarm: “I feel a personal stake because I got them to agree to give up their nuclear weapons. And none of them believe that Russia would have pulled this stunt if Ukraine still had their weapons.”"
Hence, MSC, no matter what reasons you think Russia was warranted to attack Ukraine, no way would they have done it if: 1) Ukraine had kept their nukes, and 2) the U.S. had used their nukes to defend Ukraine.
A lesson seems to be ... (for Australia) ... prepare to defend yourself as if there were no allies coming to help. Sure, the U.S. has helped, but the Biden administration has stopped Ukraine from firing long-range missiles that can target Moscow. So Russia can pulverise Kyiv, but Kyiv is not allowed to pulverise Moscow - that is why the war, on that basis, is not winnable.
Australia ought to gear up for nuclear weapons, get ready the tech, get ready the materials, so if it is ever needed we can swing into action fast.
Australia should do what Iran are doing - set up a civilian nuclear facilities, and pretend they've got nothing to do with weapons. Hey, the whole world (except US and IL) believes Iran when they say that.