Containing Ebola where it happens is of value to the world; if the places where it happens can't contain it, the consequences of spread are pretty costly for everywhere it ends up.

The article says they're looking for $25M or so. If any cases make it to the US, that much money will only cover a small number of patients. In 2014, $1M covered two patients. [1] Much better to spend the money on containment overseas than not spend it overseas and have (more) cases arrive here. It's also much better for the country where the outbreak is occuring. If said country could manage the response on its own, that would be great, but outside help in outbreaks is a good thing anyway --- there's valuable exchange of information between doctors and nurses from different areas in addition to filling the need for additional capacity for care.

[1] https://www.nbcnews.com/storyline/ebola-virus-outbreak/cost-...