Retired diplomat who testified in Trump impeachment says it is the 'American way to speak up about wrongdoing'

A career diplomat, Yovanovitch was recalled from her post in Kiev in May 2019 after allies of the President mounted a targeted campaign against her. She served as a witness in the House impeachment inquiry, testifying publicly in November as Trump attacked her on Twitter.

"I have seen dictatorships around the world, where blind obedience is the norm and truth-tellers are threatened with punishment or death. We must not allow the United States to become a country where standing up to our government is a dangerous act," Yovanovitch wrote in a Washington Post op-ed published Thursday, a day after Trump was acquitted by the Senate.

She wrote that it was "shocking to experience the storm of criticism, lies and malicious conspiracies" against her before and after her public testimony.

"But I have no regrets," she added.

On Wednesday, Trump was acquitted by the Senate of two articles of impeachment, marking the end of a more than four-month impeachment process.

CNN spoke to about half of the total of 17 witnesses as Trump's impeachment trial drew to a close. Some were angry at administration officials, including former national security adviser John Bolton, for failing to come forward. Bolton was viewed by Democrats as a key witness who could shed light on the President's decision to put a hold on security assistance to Ukraine.

The former ambassador, who recently retired, defended the State Department staff and diplomats and argued that they need "responsible and ethical political leadership."

"This administration, through acts of omission and commission, has undermined our democratic institutions, making the public question the truth and leaving public servants without the support and example of ethical behavior that they need to do their jobs and advance U.S. interests," Yovanovitch wrote.

Secretary of State Mike Pompeo had repeatedly failed to defend Yovanovitch from attacks and conspiracies during the impeachment inquiry.

"The events of the past year, while deeply disturbing, show that even though our institutions and our fellow citizens are being challenged in ways that few of us ever expected, we will endure, we will persist and we will prevail," Yovanovitch wrote.