The AI approach that’s been suggested here sounds interesting and may be the ideal solution.
I’m wondering if it would be worth looking into a less technical approach - the Suggested Topics section could contain a “Suggest Topic” button. Clicking the button would allow users to post a link to another topic on the site, and a brief description of why the two topics are related.
Not a proper mock up, but to be sure we’re on the same page, I mean something like this:
For context, I’m interested in suggesting topics that both support and counter the views expressed in a particular topic. For example, if someone creates a topic claiming that climate change isn’t a big deal, I’d like users on the site to be able to suggest related topics that either counter or support that argument.
It could also be useful for less controversial topics. When replying to a topic on here I often make use of the site’s search functionality to see if there are any related topics. The results of that effort could be preserved by allowing users to suggest related topics. As an example, reading this topic got me thinking about Discourse’s recent use of AI here: Disorder - Automatic toxicity detection for your community. It would seem relevant to me to have that topic appear in this topic’s suggested topics list, with a note mentioning that Discourse seem to be looking into ways of integrating forums with AI.