Except for some illustrative examples of what we already knew or strongly suspected about the manipulation of President Trump by various foreign leaders, we didn’t learn much from John Bolton’s new White House memoir, “The Room Where It Happened.”

We did gain, however, a stark appreciation of the difference between Mr. Bolton’s approach to public service and that of officials like former Ambassador to Ukraine Marie Yovanovitch and National Security Council Russia director Fiona Hill, who with many others testified before the House impeachment panel last fall. These officials put their careers on the line, fulfilling their obligation to work for the benefit of the American people, and not for any particular person or political party; in contrast, Mr. Bolton declined to appear before the House and instead sold his “testimony” to his publisher.

Public service and military professionals like those who testified take an oath “to support and defend the Constitution of the United States against all enemies, foreign and domestic.” The foundation of our Constitution is the rule of law, the idea that all citizens are equal before impartial justice.

Because of their commitment to the rule of law, the testifiers believed they had an obligation to inform Congress about evidence indicating possible violations of the law by President Trump and his cronies. They appeared when subpoenaed despite instructions from the White House not to, knowing they might face consequences.

Ms. Yovanovitch told the House that claims against her came from Ukrainians opposed to U.S. anti-corruption policies. Mr. Bolton says in his book that his testimony would have “made no significant difference” in the Senate outcome; the testifiers could have said the same thing, but they fulfilled their duty, appearing anyway.

Professionals like Ms. Hill understood their obligation was to provide the president with analysis and advice to ensure the security of the nation, without giving consideration to domestic electoral advantage. When called to testify, she reported Mr. Bolton’s comment that “Giuliani is a hand grenade that is going to blow everybody up.”

She was the one to set straight House members who seemed to believe it was Ukraine, and not Russia, that conducted a campaign to intervene in the 2016 elections noting that it was “a fictional narrative that has been perpetrated and propagated by the Russian security services themselves.”

Ms. Hill, an immigrant proud to have become an American, told it like it was, because she understood that her ultimate bosses were the American people. Mr. Bolton says in his book that “I thought the whole [Ukraine] affair was bad policy, questionable legally, and unacceptable as presidential behavior.”

When House Republicans questioned the testifiers’ claims because they did not have “first-hand” access to the president, Mr. Bolton’s testimony could have confirmed them; but he could not bother to tell this to Congress when he was asked.

Mr. Bolton writes that “[a] president may not misuse the national government’s legitimate powers by defining his own personal interest as synonymous with the national interest.” He quotes President Trump pleading with Chinese President Xi to help him win reelection, approving of Xi’s efforts to build “concentration camps” for members of China’s Uighur minority, and of giving “personal favors to dictators he liked.” These incidents, contrary to the democratic values that have characterized American policy for decades, would have provided valuable information for the House and Senate’s consideration of the president’s impeachment. Rather than revealing them last fall when they might have made a difference, Mr. Bolton saved them for his book and his reported $2 million advance.

National security professionals like Ms. Yovanovitch, Ms. Hill, and thousands of others throughout the government know that the politicians they serve will not always accept their advice, sometimes for good reasons, sometimes for bad. But they know who they work for — the American people — and they know what their guiding principle is — the rule of law. They also know what to choose when push comes to shove — the Constitution.

Professional government employees have been a political punching bag for decades, to the detriment of our country. But over the last year, they demonstrated character, duty, and commitment to American values that Mr. Bolton clearly does not share. So, while his book revealed few additional anecdotes to add to the president’s astounding record of misbehavior, it did reveal that Mr. Bolton’s commitment to American values paled in comparison to that of the national security professionals who sacrificed their careers to warn us all of the president’s wanton disregard for rule of law.