[semi-extrinsic]

This is also true for Scandinavian countries (and trivially true for the UK). I would guess most of Europe, really. But you probably need to learn a small bit of the local language just to shop for groceries etc.

The country I would be most hesitant about is France, they really don't like speaking English, and most French PhD theses are still written in French. This is really idiotic, all it does is slow down the dissemination of research; some acquaintances who did their PhD in France were looking hard for a non-French external examiner of their PhD, which is the easiest loophole if you want to write the thesis in English.

[yodsanklai]

> The country I would be most hesitant about is France, they really don't like speaking English

I believe it's a stereotype and it's certainly not the case in CS research labs. I did my PhD in a French research institution (INRIA). In my group, a majority of the people didn't speak French. And of course, PhD students could write and defend their thesis in English if they wanted to (I don't know if they had to find a non-French external examiner, but it's likely to be the case that some examiners are foreign anyway).

[dragandj]

This is only partly true, but even then, I wouldn't it call it idiotic. After all, can you defend your thesis in the US in French? You can't. So, why would it be idiotic for the French to expect theses at their unis to be defended in French, which is btw also an international language? It is not very pragmatic, for sure, but it has sense.

[microtonal]

After all, can you defend your thesis in the US in French? You can't. So, why would it be idiotic for the French to expect theses at their unis to be defended in French

Because English is the lingua franca of most academic fields? If you are publishing in English conference proceedings and journals, isn't it reasonable to write your thesis in English as well?

(Note that English is the default language of theses in many European countries.)

[dragandj]

Lingua Franca literally means The Language of the Franks, ie French language (pun intended)...

[collyw]

The last academic institute I worked for (in Spain) was started by people from a French institute. Mix of nationalities and they all spoke English well.