That Charlie Sheen. He’s given the whole world an excuse to root for Ashton Kutcher.

Not that Kutcher needs the help. By replacing Sheen on “Two and a Half Men,” the former “That ’70s Show” star with the so-so movie career and gaudy Twitter following enters what looks like a no-lose situation.

Why no-lose? Because if the show works, he’s a hero. And if the show doesn’t work, he moved into a difficult situation — replacing the lead on a longrunning series — that anyone, even Hugh Grant, would have been hard-pressed to save. Or at least that’s the way it can easily be spun.

As for CBS, Warner Bros. and producer Chuck Lorre, they have a real opportunity. Not only does the show get a fresh start, but Kutcher is surrounded by a deeper bench of talent than most people realize. In addition, Lorre is especially adept at writing dumb characters — something “Men” has regularly featured — so the show could go in several directions. (Kutcher doesn’t have to play a dimbulb, but he certainly exhibited a flair for doing so on “That ’70s Show.”)

The odd man out here, in more ways than one, is Sheen. The irony is that if he’d left the show quietly — to deal with his personal problems, say — Lorre almost certainly would have let the program die with its star’s exit. By trashing Lorre — a guy who hardly needs the extra work or money — so publicly and persistently, Sheen gave the producer and his team an incentive to prove “Men” can survive without him and, in essence, stick it in his ear.

Sheen also unwittingly helped provide CBS and “Men” more promotion than the show has generated in years, which will doubtless command a lot of extra attention for the fall premiere and help get the revised series sampled. And Kutcher could tap into additional younger viewers, which is obviously a priority from an ad-sales standpoint, even if the total audience drops, as might be expected.

Generally, I leave the sitcom writing to the pros, but here’s one thought: Open with Kutcher and Cryer smoking pot in the basement, at which point Cryer’s character, Alan, says, “I just had the weirdest dream.”

Yeah, on second thought, better leave it to the pros.

Oh, and speaking of pros, a footnote: I previously polled two legendary industry heavyweights, Norman Lear and Fred Silverman, regarding how they’d handle transitioning to a new actor. As I said, there are a lot of ways to go here. But for Sheen, to quote Bruce Springsteen, most of them head down, down, down.