Why is the US contribution so critical to anything outside the US when there so many other rich countries that could pick up the slack? Does this mean that besides US no one else cares? I can't believe that's true.
Because we already volunteered to do this specific thing, so it's incredibly disruptive for us to back out at (or well after) the last minute. Other countries do other things, and it would be similarly disruptive if they pulled or froze funding and operational support with 0 notice. It'd be like if Microsoft donated free copies of Windows to a hospital and then one day was like "Actually we've been donating too much…
I say we stop so other countries can spin up their own programs and pay for it. I have zero interest in using TAX dollars to fund medical programs outside the US.