But Boston isn't a particularly "Star Alliance" kind of town.
If Delta was flying BOS-ZRH then I'd say "game over" but Basel-Mulhouse-Freiburg might be right-sized for an A321 and, given its divided nationality (Swiss-French-German) the area might be not particularly wed to a European carrier (this is an area where the French Swiss and the German Swiss refuse on speaking to each other in anything except neutral English)
What's interesting an nice about Boston is just how competitive the market is to Europe.
Star Alliance - Swiss International, Lufthansa, TAP Portugal, Turkish and Scandinavia Airlines all fly to Boston non-stop. SAS is seasonal. Austrian and LOT Polish are missing.
SkyTeam - Delta, KLM, Air France and Alitalia all fly to Boston year round. Aeroflot and Air Europa are missing.
OneWorld - British Airways and Iberia. Only Finnair is missing.
If we expand to include the entire globe.
Star Alliance - United, Swiss International, Lufthansa, TAP Portugal, Turkish, SAS, Air Canada and Copa.
SkyTeam - Delta, Air France, Alitalia, KLM and Koreanair.
OneWorld - American, British Airways, Iberia, Cathay Pacific, Qatar, LATAM and Japan Airlines.
I wonder if we will ever see one of the Star Alliance Asian carriers - All Nippon or Asiana, start service to Boston.