The head of the CDC said Saturday that imposing a travel ban between the US and West African countries dealing with the Ebola virus could worsen the outbreak that has killed over 3,000 people in five countries.

“Though we might wish we can seal ourselves off from the world, there are Americans who have the right of return and many other people that have the right to enter this country,” Dr Thomas Frieden told a press conference. “We’re not going to be able to get to zero risk no matter what we do unless we control the outbreak in West Africa.”

This is carefully, cynically mendacious. “Americans who have the right of return” from western Africa are few, and they’re easily controlled at the point of departure until they can be shown to be Ebola-free. Those infected can be brought back under suitable controls, as has already been demonstrated.

Moreover, there are not at all very “many other people that have the right to enter this country;” that’s the point of border control: no nation has an obligation to let any non-citizen enter, except as that nation sees fit.

Frieden compounded his…error…with this:

We really need to be clear that we don’t inadvertently increase the risk to people in this country by making it harder for us to respond to the needs in those countries by making it harder to get assistance in and therefore those outbreaks would become worse, go on longer, and paradoxically, something that we did to try and protect ourselves might actually increase our risk.

This is more nonsense. A travel ban would be on travel from western Africa, not to it. Even were such a ban to include to western Africa, exceptions for humanitarian purposes are easily defined.

We don’t get to zero risk by restricting travel from enemy nations during time of war, either, until we control and terminate on our terms the war at its source; however, we routinely and effectively reduce risk by such restrictions. So it is here. Ebola isn’t a shooting war, but it is a war against a virus that has devastating effect wherever it invades. Travel restrictions would significantly reduce risk.