Easier to obtain permanent position in Europe after being faculty in US? I am currently considering junior faculty positions in the US and Europe—my partner is European, and for a variety of reasons (family, etc.) we would like to end up there in the long term.  Being from the US, however, it is unclear to me which is a better strategy for obtaining a permanent position:


get tenure (or at least, "be successful") at a good North American department and use that leverage to negotiate a position in Europe, or
spend that same time / energy making personal connections in Europe.


The reason that the answer is not clear to me is that 1. the country in question has a relatively small number of permanent positions, and 2. my impression is that in many European systems, personal contacts still have a rather significant effect (even among candidates with excellent qualifications).

I am interested in both quantiative data (e.g., what percent of hires are domestic vs. foreign in various countries/systems) as well as personal experience.

Thanks!
Are you actually deciding between particular positions in Europe and in the US?  It's not clear to me what you are actually suggesting doing in option 2. There's no question that you should be making personal connections in Europe, particularly whatever country you're hoping to move to, but unless you have a job offer there, you should just try to find a position where you can be successful and reasonably happy, whichever continent it's on. 

I think it is true that it's dangerous to take a position, thinking you'll move later.  A lot of people find it harder than they think; in a lot of cases this is more because they get settled and lose their motivation, rather than it actually being out of reach.  

As for how serious a possibility it will be to move later if you're starting a position in the US, I think this is the wrong forum to ask.  You should find a senior person you can somewhat trust in your target country and ask them (if you don't have such a person, try to cultivate them).  It's going to vary a lot depending on the country, the field, and unfortunately with time (just because it seems hard now, the situation might change later), so I don't think general facts will help you much.