Lt. Col. Alexander Vindman, a key witness in the impeachment trial of President Trump, will retire today.

Vindman is retiring "after it has been made clear that his future within the institution he has dutifully served will forever be limited," his lawyer, Amb. David Pressman, said in a statement. Recently, controversy has grown over an abnormal stall in his promotion to the rank of full colonel.

"Over the last months, LTC Vindman has been guided by a very simple and very American principle: 'here, right matters.' He has spoken publicly once, and only pursuant to a subpoena from the United States Congress. Compelled to testify, this decorated soldier was thrust into a conversation that goes to the heart of our country's values, and its future," the statement continued.

"Through a campaign of bullying, intimidation, and retaliation, the President of the United States attempted to force LTC Vindman to choose: Between adhering to the law or pleasing a President," Pressman wrote. "Between honoring his oath or protecting his career. Between protecting his promotion or the promotion of his fellow soldiers. These are choices that no one in the United States should confront, especially one who has dedicated his life to serving it."

Trump fired Vindman from his White House National Security Council assignment in February.

Last week, Sen. Tammy Duckworth said she would put a hold on the promotions of more than 1,100 senior Army officers unless the Trump administration guaranteed in writing that if Vindman were on a Pentagon promotions list, as was expected, the White House wouldn't interfere with his promotion to full colonel.

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