[marcf]

I would argue the issue is more about the priorities of the American government and also its economic decline. America has fundamental issues that means it can not longer fund such a mission, but it is likely that other governments and economies that are healthier and with different priorities could do manned missions to the moon.

It is important to differentiate between human capacity and the capacity and priorities of the American government. They are not the same thing, even if when one lives in the US, it can seem like it.

One could argue (similarly incorrectly) that human capacity in Britain peaked in the late 1800s, but again that was because that was the peak of the Britian empire.