The position I applied for was advertised as Associate Professor with Tenure, but now they’re saying it’s tenure-track Associate Professor I am an associate professor, who has received tenure in the US in 2014. After receiving tenure, I moved to Europe to help my family with some health issues, and found an associate professor position in a country where tenure is 'by law' meaning the position cannot be revoked or taken away. I am now looking to return to North America, and have begun to apply for associate professor job openings.

I have applied for a position as tenured associate professor. I interviewed and was told I was selected by the department as their top candidate. However, the dean at the new institution just emailed me that the new position will be associate professor "tenure-track," meaning I would need to apply for tenure within 4 years.

Clearly, what I had applied for is not what I am being offered. In my view, there is a flaw in their advertising. The position description clearly stated "the University of X invites applications for a tenure-track Assistant Professor or Tenured Associate Professor in...."

While I understand that each university has its own interest in mind, this seems like a very bad start of a relationship. If I accepted this demotion, I would probably do so with some resentment. The University in question is academically equal to the one I first received tenure from. 

I am seeking advice on how to respond to this proposition and would be very grateful to hear people's opinions.
Based on what you've said,


  In my view, there is a flaw in their advertising. The position description clearly stated "the University of X invites applications for a tenure-track Assistant Professor or Tenured Associate Professor in...."


Well...yes, you're exactly right.  It sounds like the department and the dean were not on the same page when the position announcement was posted.  


  While I understand that each university has its own interest in mind, this seems like a very bad start of a relationship. If I accepted this demotion, I would probably do so with some resentment. The University in question is academically equal to the one I first received tenure from. 


Again, I agree completely.  You've had two different tenured positions, including one at a US institution of (you say, and I'm going with it) comparable academic quality to the one you're applying for.  You applied to this position and interviewed for it -- presumably taking some trouble doing so, since you now live in Europe and have family there -- based on the information you received in writing that it would come with tenure.  Only at the end of the process have you been informed otherwise.  Well...yes, that's a seriously alarming bait and switch.

In my opinion there is really only one thing to do.  You should respond by calling attention to precisely the facts you mentioned to us, especially that (i) the position was advertised as with tenure and that's why you applied for it and (ii) your last two academic jobs have had tenure, including at US institution X (you don't need to explicitly say that it's of comparable academic quality; I would leave them to claim otherwise if they want to), that you are very excited and interested in the job, but only under the original terms: you are not contemplating making an international move from a permanent academic job to a possibly temporary one.

In other words, I think the issue is serious enough to prevent you from taking the academic job...again, for exactly the reasons you say.  The type of employer who will not be held to what they told you before is exactly the type of employer to cause you N years of deep worry that they might not give you tenure, and nothing in your question suggests that you should subject yourself to that.  

I really hope that they respond well to your holding your ground. Good luck!