These actions are for the ~5-10% of people who get this bug and who require intensive care in order to survive. The death rate is pretty low even for those who end up with severe symptoms if the full weight of modern medical technology and care can be applied to their recovery.

Right now, as I type this, many hospitals in the United States have had all of their excess intensive care capacity used up by Covid-19 cases. Not all, but many.

Once large groups of hospitals reach capacity, then there will be no choice but to black tag people who could otherwise be saved and leave them to die in the hallways.

Click this graph, then click Logarithmic at the top: https://mackuba.eu/corona/#united_states

You're right to note that this is a global problem. Given that, the vast majority of human to human contact is NOT cross border.

This bug is probably going to end up infecting most of the people in the United States. The main thing we can do at this point is to keep hospitals from being too overwhelmed, to keep the number of black tagged people, dying in the hallways, to a minimum.