Marie Yovanovitch is the rare diplomat who achieved celebrity status. For that she can thank Donald Trump, who had her dismissed as ambassador to Ukraine for failing to cooperate with Rudy Giuliani in his quest for dirt on Joe Biden’s son, Hunter, for whatever he was doing as a director of Burisma, the energy company at the heart of the investigation.

Ms. Yovanovitch, in her memoir “Lessons from the Edge,” portrays herself as a good woman wronged while serving the interests of the United States. From humiliation came the adoration of the enemies of Trump world that had ganged up on her to end her career as a foreign service officer. 

It’s tempting to treat Ms. Yovanovitch as a hero, but certain questions arise that she doesn’t quite address — or even recognize. The book raises the issue of the degree to which an ambassador, any ambassador to any country, should get involved in the internal affairs of a foreign country.

Ms. Yovanovitch, in a series of diplomatic posts, notably Armenia and Kyrgyzstan before her second, final tour in Ukraine, had crusaded mightily against wrongdoing in high places. One thing she says she learned was that it is a mistake to believe that “winking at a corrupt leader would strengthen our national security.”

The corruption at the highest levels in Ukraine might have been greater than in any of the smaller countries in which she had served. She had to struggle with the highest officials to get them to recognize, much less confront, the problem, and then she had to deal with Mr. Giuliani wanting to get the goods on Hunter Biden.

“I had known going into the job that I wasn’t going to make friends by pressing for reform,” she writes. As Mr. Giuliani persisted, in league with a corrupt Ukrainian politico, she writes, “The notion that an unscrupulous, disgruntled foreign official or even a president’s personal dirt digger could actually manipulate the U.S. government to act against a sitting U.S. ambassador was inconceivable to me.”

Yet Ms. Yovanvitch was proven wrong when a colleague at the State Department called urgently even as she was entertaining at her ambassadorial residence. Summoned to Washington, she was let go while assured she had done no wrong.

It was not until later that President Trump pressured the newly elected president, Volodymyr Zelensky, asking him “to do us a favor” after Mr. Zelensky had asked for Javelin missiles. Mr. Trump also told Mr. Zelensky that Ambassador Yovanovitch was “bad news and the people she was dealing with in Ukraine were bad news….”

In retrospect, should Ms. Yovanovitch have parried Mr. Giuliani’s interference and, if so, how, and should she as a dutiful diplomat have gone along with Mr. Trump’s desire to go after Hunter Biden?

In her book she exonerates from blame Hunter, and, indirectly, his father, who she notes as vice president had been “President Obama’s lead person for Ukraine.” I’m not sure that was such a good idea. While Hunter Biden may not have been doing anything legally wrong, he was getting paid what mere mortals would regard as an enormous sum, a million dollars a year, for sitting on Burisma’s board.  

What did Hunter Biden do for all that easy dough? Did he go to Kyiv for board meetings now and then or just chat via Zoom or whatever? And did Marie meet Hunter and talk over his activities?

The ambassador might respond, as did Hunter’s father, that what the vice president’s son did was his business, not hers or America’s, but she is the one who represents herself as so all-fired interested in corruption in high places. Might she not have been a little curious about Hunter too? Did she wonder why Burisma had placed someone on its board who knew nothing about what he was doing?

Ms. Yovanovitch gets total sympathy, unstinting support from her friends and advocates. It might be difficult to dispute her belief in “the need to hold accountable an American president who, with his enablers,” had pursued “his own self-interest….”

Explaining her eagerness to testify at a secret hearing that led to President Trump’s impeachment, she writes that she had “never thought that I would be alarmed about the resilience of American institutions or the integrity of our leaders.” It was, she tells us, “a national emergency.”

It might be true the American system as she experienced it was not living up to expectations. I still want to know why she lets Hunter Biden and Joe Biden completely off the hook. If the money Hunter was making off Burisma wasn’t a form of bribery, I don’t know what is. And if she thinks he wasn’t being paid off to get through to Daddy, it’s hard to take her at face value. One gets the sense that the ambassador has more to tell us that she’s not saying in this book.