Asked to write a letter of recommendation for promotion for an abusive former professor I've recently been asked to write a letter of recommendation for tenure and promotion for my former advisor from graduate school. This is for a potential promotion/tenure a few years down the line.

My time in grad school was one of the darkest periods of my life. My former advisor was verbally abusive, demanding, and insulting. The way they treated me, and the stress that came with it, led to severe problems with anxiety and depression to the point where I became suicidal. I'm also not the only student who's had these kind of problems with them: I know of at least one other student who's had serious mental health problems due to their experiences as their graduate student under the same professor.

The problem is I'm still potentially reliant on my former advisor. I'm now working full-time outside academia, and I'm applying for employment-based permanent residency in the United States. One of the requirements for that is a set of experience letters from a few previous employers or professors that states what skills you're bringing to the job (to justify why the company is hiring you instead of an American). This is a signed letter saying something like:


  This person was a student of mine from date A to date B, I have direct personal knowledge of their work, they took courses on X, Y, and Z topics, and demonstrated skills A, B, and C through the course of their research/work.


This advisor has already refused to sign such a letter for another student who left the lab on bad terms after standing up to the abuse.

Without permanent residency, I'd be forced to leave the country in the coming years when my work visa expires. I've spent long enough here that my entire life is here, and so anything that could potentially put it in jeopardy makes me extremely cautious.

The request states that my letter will be kept confidential, but my former advisor has supervised relatively few students overall. My understanding is that any points I bring up in my letter will be discussed with them as part of their review process, and so there's a good chance they'll know it was me.

I see three possible options:


Write the letter honestly, holding them accountable for their actions, but leaving myself open to the risk that they'll know I wrote something negative and retaliate by refusing to cooperate with my immigration process.
Politely decline to write the letter, which doesn't hold them accountable, and could still cause them to refuse when I ask them for the favour of signing the experience letter.
Grit my teeth and write something reasonably neutral in the letter, letting them potentially go on to harm more students in the future.


None of these are good options, and I'm not sure what the best course of action here is.
Get your former advisor to sign the letter now.

After that has succeeded or failed, you should contact the person who runs this process and ask them verbally how the letter will be used and what it contains.  Probably this is a dean.  Probably the dean already knows about your advisor's behavior.  They might be seeking a letter that will help them get rid of your former advisor.  At well-run universities, these letters are not requested from random students.  They come from known students.

You should write an honest letter.

There is an option you do not mention:  You can "damn with faint praise."  This is done by writing a letter which says nice things about a person, but none of the nice things are relevant to the person's job.  E.g. They are funny and well-dressed.  I don't recommend this but it is available to you.  If done carefully, it can prevent promotion while giving the illusion that you intended to help the advisor.