Army Lieutenant Colonel Alexander Vindman, the White House National Security Council's top Ukraine expert, testified at the third public impeachment hearing before the U.S. House of Representatives Intelligence Committee, wearing his blue dress military uniform and medals.
Vindman and a second witness - Jennifer Williams, an aide to U.S. Vice President Mike Pence - raised questions about requests made by Trump in a July 25 telephone call with Ukrainian President Volodymyr Zelenskiy that is at the heart of the impeachment investigation threatening Trump's presidency.
During the call, Trump asked Zelenskiy to carry out two investigations that would benefit him politically including one targeting Democratic political rival Joe Biden.
Sean Maloney asked, "When you heard him say that, what was the first thought that went through you mind?" Vindman responded by saying, "Frankly, I couldn't believe what I was hearing.
It was probably an element of shock that maybe in certain regards my worst fear of how our Ukraine policy could play out, was playing out - how this was likely to have significant implications for U.S. national security."