Even if that's true -- and people asserting that never support it -- I don't see what the point of that is in defense of the status quo US policy. If that is the reason that Americans are paying so much more for healthcare and not getting any more benefits, it would be better for Americans if the US stopped doing that.
If the US stopped doing that there's no reason to assume that another country would magically step up to the plate. What if, as is the point of the article, the US stopped doing that and the world simply stopped getting as many new drugs?
> If the US stopped doing that there's no reason to assume that another country would magically step up to the plate.
Another country, no, because that would be irrational and stupid (just as it would be for the US, if the argument atht the US is actually doing that is correct.)
On the other hand, if the US is subsidizing the rest of the world, that means the US is substantially reducing the marginal benefit of expenditures in the subsidized domain by other countries, disincentivizing their own expenditures (direct or through policy which promotes drug development.) It would be irrational to expect the removal of that subsidy and the associate disincetives not to result in increased expenditures.