According to respected epidemiologists I've seen quoted, closing borders against one or a small number of nations amounts to nothing better than performance pol

According to respected epidemiologists I've seen quoted, closing borders against one or a small number of nations amounts to nothing better than performance politics theatre and is of utterly no practical use in slowing or preventing transmission. If we accept that, then it looks a lot like a selective prejudice at work rather than a part of a rational process. Closing all borders might, I guess, be somewhat effective.