It also makes the point that, under some reasonable assumptions, you could assume that any domestic program you could theoretically redirect the funding to would likely be ~100x less effective than PEPFAR, which is an abnormally effective aid program.
Reasonable assumptions would not assume you to assuming the US' top medical bureaucrat being a conspiracy theorist who denies the existence of HIV (and asserts AIDS is environmental and that anti-retroviral drugs are dangerous toxins).
It also makes the point that, under some reasonable assumptions, you could assume that any domestic program you could theoretically redirect the funding to would likely be ~100x less effective than PEPFAR, which is an abnormally effective aid program.