Sadly, the United States used to have a treaty law in place that delivered the easy solution you describe. In mid-2020, the treaty was found not to provide the

Sadly, the United States used to have a treaty law in place that delivered the easy solution you describe. In mid-2020, the treaty was found not to provide the necessary protections, and invalidated by EU courts; no replacement treaty was negotiated or signed by the US, and so here we are.