Former Ambassador William Taylor leaves a closed door meeting after testifying as part of the House impeachment inquiry into President Donald Trump, on Capitol Hill in Washington, Tuesday, Oct. 22, 2019. (AP Photo/Andrew Harnik)

The following column is the opinion and analysis of the writer.

The White House lashed out at respected diplomat William Taylor after his testimony in the House impeachment investigation this week. Its reaction was unequivocal, insulting — and dead wrong.

Taylor, acting ambassador to Ukraine, explained in careful detail that he saw President Donald Trump tie military aid to a public commitment by the Ukrainian president to investigate Joe Biden, contradicting Trump’s claims that there was no quid pro quo in the conversations.

Trump officials quickly trash-talked Taylor, saying his testimony was part of “a coordinated smear campaign from … unelected bureaucrats waging war on the Constitution.” This was in line with the reaction last week of acting White House chief of staff Mick Mulvaney, who dismissed earlier testimony from the likes of veteran diplomats Marie Yovanovitch and George Kent as coming from “mostly career bureaucrats who are saying, ‘You know what, I don’t like President Trump’s politics, so I’m going to participate in this witch hunt that they are undertaking on the Hill.’”

I don’t know any more about diplomats Taylor, Yovanovitch and Kent than I’ve read. But I have observed firsthand the rigorously nonpartisan culture in our Foreign Service, which is not well-understood by most Americans. For more than a decade, I have occasionally traveled overseas as part of the State Department’s U.S. Speakers Program. Why me? For many years now, under administrations of both political parties, the United States has fostered the rule of law abroad. The State Department apparently thought an American novelist and lawyer, who writes about the law and whose books have been frequently made into movies, might offer a more engaging approach to that topic for a foreign audience than, say, a law professor. Since 2008, I have been dispatched to, among other places, Argentina, Austria, China, the Czech Republic, the Republic of Georgia, Israel and Russia.

One of the biggest revelations to me on these trips has been meeting dozens of officers of the U.S. Foreign Service. To a person, they struck me as remarkable, both for the depth of their intelligence and their devotion to our country. We routinely honor the members of our armed services. But our Foreign Service officers are entitled to almost the same level of veneration. Thirteen thousand serve at 256 posts around the world, implementing U.S. foreign policy and helping Americans abroad. Their careers frequently keep them far from home and family, often in unglamorous or even dangerous locations. Chris Stevens, our ambassador to Libya, had been a Foreign Service officer for more than a decade when he was killed in the infamous Benghazi attack in 2012.

Entry into the Foreign Service is highly competitive, involving written and then oral exams. Only 1 in 10 candidates is ultimately hired. And the competition does not end then. There are annual ratings and an up-or-out promotion system. At the top level is the Senior Foreign Service, requiring a presidential appointment, the rank occupied by Taylor and Yovanovitch. Senior officers sometimes become U.S. ambassadors, especially in locations like Ukraine, where expertise in local affairs is essential in representing us.

FSOs implement the policies determined in Washington, whether or not they agree with them. They know that over the course of their careers they will serve under Democrats and Republicans, and that it would inevitably be detrimental to their advancement to be outwardly identified with either party. On the job, they express no political opinions.

I happened to be in Israel on one of these trips, in December 2016, when the Trump administration announced it would move the U.S. Embassy from Tel Aviv to Jerusalem. Congress had mandated this change in 1995, but previous administrations had deferred what was widely regarded as an inflammatory action. To the FSOs in Tel Aviv, the announcement meant they would have to move, uproot their families and work every day at a site that would be a top potential terrorist target. But I heard nothing critical from anyone. They accepted the right of a new administration to make new policy.

That is the professional culture of Taylor, Yovanovitch and Kent. Taylor is a graduate of West Point and a Vietnam combat veteran who has a graduate degree from Harvard. He served in foreign service assignments to the Middle East before becoming ambassador to Ukraine under President George W. Bush. He returned from retirement last summer to become acting ambassador there at the request of the White House. Yovanovitch, a Princeton graduate, joined the Foreign Service in 1980. Bush nominated her to be our ambassador first to Kyrgyzstan, then Armenia, before President Barack Obama chose her to serve in Ukraine. Kent, a deputy assistant secretary of state, joined the Foreign Service in 1992, with degrees from Johns Hopkins School of Advanced International Studies and Harvard.

The three have been described by colleagues as discreet, meticulous and down the middle. Kent, for example, not only testified about the Trump administration’s machinations in Ukraine. He also reportedly said he’d told Biden’s staff in 2015 that Biden’s son’s role with Burisma, a Ukraine energy company, created the appearance of a conflict of interest.

The Trump administration’s effort to dismiss these three as political hacks and “bureaucrats,” implying that they are mere paper-pushers who stepped from obscurity only to smear the president, ignores the truth that they are all front-line diplomats who have served American interests abroad for decades under both political parties. Like their thousands of colleagues in the Foreign Service, they are entitled to our thanks and respect, not vilification by the White House.

Scott Turow is the Chicago-based author of “Presumed Innocent” and “The Last Trial,” which will be published next May. He wrote this for the Chicago Tribune