It's simple: they can't. Anywhere with non-trivial amounts of community transmission would have negligible additional risk by allowing those workers to enter, e

It's simple: they can't. Anywhere with non-trivial amounts of community transmission would have negligible additional risk by allowing those workers to enter, especially if symptoms are screened. A handful of new cases is a drop in a very big bucket. That's been true over almost the whole world for months, because covid has spread to pretty much the entire world. These workers have been imprisoned because of politics, not science.