In reimposing travel curbs on Americans, the European Union is sending a message to the U.S. that is as much about diplomacy as it is about epidemiology.

Sure, there is data to nominally support the decision. A surge in cases driven by the delta variant’s spread has put the U.S. well beyond the recommended limits for nonessential travel to the EU.

There have been 588 new cases per 100,000 inhabitants in the two weeks ending Aug. 22, versus the guideline of 75. The U.S. was classified as "high-risk” by Germany back on Aug. 15.