The difference is mostly made up in Defence pensions, which NATO would count as military spending but Australia does not. The relevant political context is clear: the current US administration talks about defence spending in percentages of GDP to its allies and expects an answer in kind. NATO has a bespoke method of calculating defence spending. For instance, Australia’s cash spent investing in defence industries, here or abroad, would have to be taken out: it would count as defence-related spending for NATO purposes, not defence spending proper. In government accounting, there are often several numbers that can legitimately claim to be ‘defence spending’.