There is another way of looking at this. If an area has contained it once, they have to do it again. They have to try. They are not immune. If the US decides

There is another way of looking at this. If an area has contained it once, they have to do it again. They have to try. They are not immune. If the US decides to go it alone on the herd immunity approach, because they are incapable of making any other approach work, and all other countries reduce the infection rate to close to zero over the summer with the lockdown approach, that US travel ban aint getting lifted. Most countries have attempted lockdown, opening up as and when their health services are able to cope. If US citizens were immune but contagious, US citizens would only be free to travel within US borders. Could end up with Lockdown, branded as freedom. In that light it makes sense to what ever the rest of the world does.