Everything you need to know about how Donald Trump views his months-long haranguing of Megyn Kelly is contained in one answer to one question posed by the Fox News star during her highly anticipated interview with the presumptive Republican presidential nominee Tuesday night.

KELLY: So when you look back on the past nine months, from that first debate until now, any regrets?

TRUMP: Absolutely, I have regrets. I don't think I want to discuss what the regrets are, but absolutely I could have done certain things differently. I could have maybe used different language in a couple of instances. But overall, I'd have to be very happy with the outcome. And I think if I didn't conduct myself in the way I've done it, I don't think I would have been successful. Actually, if I were soft, if I were "presidential," okay — in a way it's a bad word; there's nothing wrong with being presidential — but if I would not have fought back the way I fought back, I don't think I would have been successful.

Translation: Sorry not sorry.

Saying he has regrets is about as close to an apology as Trump ever gets. But he was clearly talking only about a few specific remarks or tweets -- not his overall approach. He doesn't regret bashing Kelly because the result was good — he's the GOP standard-bearer, meaning anything he did along the way helped him or, at the very least, didn't hurt him. So what's to be sorry about?

Machiavelli would be proud.

The Trump-Kelly saga began, of course, Aug. 6 at the first debate of the Republican primary season. This question from Kelly set Trump off — but not right away.

KELLY: Mr. Trump, one of the things people love about you is you speak your mind, and you don't use a politician's filter. However, that is not without its downsides — in particular, when it comes to women. You've called women you don't like “fat pigs,” “dogs,” “slobs,” and “disgusting animals.” … Your Twitter account has several disparaging comments about women's looks. You once told a contestant on “Celebrity Apprentice” it would be a pretty picture to see her on her knees. Does that sound to you like the temperament of a man we should elect as president? And how will you answer the charge from Hillary Clinton, who is likely to be the Democratic nominee, that you are part of the war on women?

Trump seemed ready. “I think the big problem this country has is being politically correct,” he replied. The crowd applauded. Trump went on about the scourge of political correctness and then said this:

TRUMP: Honestly, Megyn, if you don't like it, I'm sorry. I've been very nice to you, although I could probably maybe not be, based on the way you have treated me. But I wouldn't do that.

Oh, but he would. A question Trump seemed to handle just fine in the moment gnawed at him overnight. He started by tweeting that she had “bombed” as a moderator.

Appearing on CNN the next night — during Kelly’s time slot on Fox News — Trump got personal as he complained about her line of questionng.

“You could see there was blood coming out of her eyes, blood coming out of her wherever,” he said.

From then until Kelly paid a visit to Trump Tower last month to “clear the air,” as she put it, and request the interview that aired Tuesday, the real estate mogul was almost relentless. He ripped her regularly on Twitter, boycotted a second debate she was scheduled to moderate and effectively forced the cancellation of another by refusing to participate.

He did appear at one other debate featuring Kelly — the one where he bragged about the size of his hands and his, ahem, “something else.”

But Trump hadn't sat down with Kelly, one on one, since their one-sided feud began.

For now, all is quiet on the Kelly front. (Get it? He revealed in the interview that his favorite book, other than the Bible and "The Art of the Deal," is "All Quiet on the Western Front.") Trump even tweeted a compliment after the telecast.

But there's no guarantee things will stay this way.

"This could happen again with us," Trump said at one point, referring to the possibility of another feud. It's clear from his response to Kelly's question about regrets that Trump won't hesitate to attack again in the future if he believes more insults will work to his advantage.

The only thing that seems to have changed is the political calculus. Before, shredding Kelly burnished Trump's reputation as a take-no-guff tough guy; now, making amends enhances his image as a unifier who can win the general election.

With Kelly — and everyone else — Trump seems capable of being anything he needs to be in the moment. Anything but genuinely sorry.