Weird assumption! Generally speaking, academic research is considered to be an international, or super-national, cooperative effort in most fields.
I have just realized that I assume this to be the case. If a government ever does that is simply a collateral effect of their main purpose which is enrichment of the politicans involved in the process.
> The presumption you're making is that a country would never spend money for the public good, where that is defined to include the entire human race, rather than just nationals.
I think in general this is the case? Obviously governments budget for foreign aid, and also contribute to collective efforts e.g. climate change or (relevant to this discussion) EU funds such as Horizon 2020. But I don't think any governments do/should consider "the public" as meaning "the entire human race".
Read Nussbaum's book about cosmopolitanism - the introductory chapters provide plenty of evidence that historically speaking, elites have conceived of governments has having at least some obligation to all human beings, regardless of state.