• Vindman is one of the most significant and damaging witnesses to testify so far in the impeachment inquiry into President Donald Trump .
  • Vindman has direct knowledge of the phone call at the center of the impeachment probe, and he also confirmed that Trump engaged in a quid pro quo with Ukraine's president.
  • Scroll down to read the key takeaways from Vindman's blockbuster testimony.
  • Visit Business Insider's homepage for more stories .

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House Democrats released the transcript Friday of some of the most damning testimony given so far in the impeachment inquiry into President Donald Trump .

Lawmakers released transcripts on Friday of the depositions of Lt. Col. Alexander Vindman, the top Ukraine expert on the National Security Council, and Fiona Hill, the former senior director for Russian and Eurasian affairs.

Vindman, a military veteran and Purple Heart recipient, is one of the most significant witnesses against Trump. He has direct knowledge of the July 25 phone call between Trump and Ukrainian President Volodymyr Zelensky during which Trump repeatedly pressured Zelensky to launch politically motivated investigations that would help Trump's 2020 campaign.

Vindman was so alarmed by the call that he immediately reported what he'd heard to John Eisenberg, the top lawyer for the National Security Council. He testified to Congress that Trump's demands of Zelensky forced him to make a "moral and ethical" decision and fueled concerns that Trump's actions could "undermine US national security."

According to the transcript of his testimony, Vindman also outlined in detail the pressure campaign that Trump and his allies carried out to strongarm Ukraine into acceding to his demands. That campaign included, among other things, freezing vital military aid to help Ukraine fend off Russian aggression and dangling a White House meeting with Trump in exchange for the investigations.

Here are some of the biggest takeaways from Vindman's blockbuster testimony:

  • A White House meeting was "what this was about. This was about getting a White House meeting. It was a demand for [Zelensky] to fulfill his fulfill this particular prerequisite in order to get the meeting."
  • Vindman immediately flagged Trump's behavior to legal advisers in the White House.
  • "I did convey certain concerns internally to national security officials in accordance with my decades of experience and training, sense of duty, and obligation to operate within the chain of command," he testified. "As an Active Duty military officer, the command structure is extremely important to me. On many occasions, I've been told I should express my views and share my concerns with my chain of command and proper authorities. I believe that any good military officer should and would do the same, thus providing his or her best advice to leadership."
  • Vindman became aware of Rudy Giuliani's involvement in the pressure campaign in mid-April.
  • He also testified that there's no evidence to support Giuliani's smear campaign against Masha Yovanovitch, the US's former ambassador to Ukraine who was abruptly ousted in May.
  • "I am unaware of any factual basis for the accusations against Ambassador Yovanovitch, and I am, frankly, unaware of any authoritative basis for Ukrainian interference in 2016 elections, based on my knowledge," Vindman said.

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