Ask HN: Could a form of modern-day AI been made to work back in the late 1980s?

Before you answer with a loud "No," this isn't a question that asks for facts. Of course, it didn't. But also, we also know that the underlying theories behind LLMs and other artificial intelligence techniques are not new; some date back to much earlier. Plus, there were efforts on both sides of the Cold War sectrum to build a supercomputer "to rule them all."

Thus, if we imagine that the scope of my question is in the context of a parallel reality hard-sci-fi story, how plausible would it have been for any side to advance over the other with any form of artifical intelligence (as rudimentary as it may have been)?