What is a better point in an academic career to move to the U.S.: as an assistant professor or after tenure? I am starting my second academic year as an assistant professor at a university in Europe. I'd like to move back to the US at some point in the near future. If I stay at my current university for 2 or 3 more years, it's likely that I will be offered tenure. Based on the openings I see in the US in my field, there are more assistant professor positions than associate professor positions. 


Will it be better for my career prospects to apply now for assistant professor jobs in the US? If so, should I expect a reduced tenure clock?
Or should I wait a few more years and with tenure under my belt, apply for associate professor jobs?
As someone who is just now making such a transition, my sense that it's hard to make the transition in either direction at any stage of your career.

My sense is that as a less senior faculty member, you'll have an easier time getting things going, because the expectations on junior faculty are lower in the sense of ramping up the group in the first few years. But whether or not you should wait is really a function of what you're looking for in your career.