Originally Posted by
fumje
In general I would say the best arrangement is to avoid third-country transit, i.e. book travel with a nonstop flight between your departure and destination countries. That avoids the morass of transit rules which I'm sure will linger for quite some time.
However, if you see there is a large price difference for ticketing to France vs. to Switzerland, it may be worth the gamble. As noted, Europe / US travel restrictions may loosen before too long. But of course they may tighten again.
This is good advice. When you involve three countries you are going to have work with the least common denominator on what’s permissible, I.e. French, Swiss & US rules and the general pattern of ”have you visited country XYZ in the last 10 days” which may still be in effect in December. Right now there are major differences between the European countries.