If for every tit dollar you spend on outer prevention you can stop some tat percentage of disease spread both inwards and outwards, and then that has a provable impact on your own economy, I'd say playing the geopolitical sugar daddy is no selfless act neither in ther short term nor the long term.

I understand the need for assurance that those dollars are effectively working towards the intended goal, but assuming you are a sucker for paying the bill is only right if there was nothing of nutritional value to you in the menu.

So I guess the question is about working the data and crunching the numbers to know whether there is or isn't impact on your own economy and the welfare of your population, and not about not feeling like a sucker on the supranational ego scene.

Comparing only the money spent seems awfully naive. The US is definitely not the "loser" in its global hegemony.