I always write "Zurich" in English texts, simply because most native English-speakers do not know what those two dots are for. Worse even if you wrote "München" instead of "Munich." Moreover, with Micro$ofts notoriously inconsistent handling of diacritic marks such as German umlauts you never know what appears on the screens of other computers.
Of course you are right in going on using "Zurich," and that not only because it's absolutely correct in French. From my point of view the distinction made by the Britannica simply doesn't make sense.
Ahmed, many place names have undergone very extensive changes of spelling and pronunciation in the course of time, often caused by changes of the cultural surroundings. For instance, Tripoli originally was Greek "Tripolis" ("Three Towns"), so it hasn't changed much in European languages, but please don't ask me why it changed so much more in Arabic. Naples was Neapolis ("New Town" in Greek), now Napoli in Italian. Not very much of a change either. On the other hand, Istanbul comes from Greek "Eis ten polin" ("In the town"), quite a difference both in spelling and pronunciation. What's more, that town has even undergone several changes of names due to political reasons: Byzantium -> Constantinopolis -> Istanbul.
Germania was the Latin name for the whole area settled by the Germans. One of their southern tribes were the Alemannic ("All Men"), who eventually threw the Romans out of the area north of the Alps. That's why my native language is southern Alemannic, aka Swiss German.
The Greeks still call Switzerland "Elvetia," and the nation's name on Swiss post stamps is "Helvetia." That's the Latin name of the area settled by the Celtic tribe of the Helvetii before Julius Caesar conquered it around 58 B.C., as described in his "De Bello Gallico." By the way, the name "Switzerland" ("Suisse" in French, "Svizzera" in Italian, "Svizra" in Reto-Romansh) comes from Schwyz, one of the three cantons that founded the Confoederatio Helvetica (Swiss Confederation) in 1291 A.D..
Reply from Hans Joerg Rothenberger (Walenstadt - Switzerland)