The two-time Oscar winner Kevin Spacey said last month that he was ready to return to acting after years in the wilderness following sexual assault allegations.

“I know that there are people right now who are ready to hire me the moment I am cleared of these charges in London,” Mr. Spacey told a German magazine, referring to accusations that he had assaulted four men. “The second that happens, they’re ready to move forward.”

Mr. Spacey was right in several ways: A British jury found him not guilty of nine counts of sexual assault this week, nearly a year after a federal jury in Manhattan cleared him of battery in a civil case filed by the actor Anthony Rapp. And he has two small projects awaiting release, with directors who could not be more publicly supportive.

But the starry Hollywood roles, like Mr. Spacey’s conniving politician in “House of Cards” and droll advertising executive in “American Beauty,” may not come back anytime soon, if at all.

Despite Mr….