Some of Alexander Vindman's fellow soldiers have blasted him for testifying in uniform during the House impeachment hearings, accusing him of politicizing the military by stating personal opinions that were highly critical of President Trump.

Vindman, 44, the National Security Council’s Ukraine director, was thrust into the political spotlight when he testified before Congress on Oct. 29 as one of the few people who listened in on a July phone call between Trump and Ukrainian President Volodymyr Zelensky.

His appearance in uniform has been a point of contention. Military members detailed to the NSC typically wear suits but Vindman gave his testimony in uniform, and was lauded for having been awarded a Purple Heart for being wounded in Iraq, and a Combat Infantryman's Badge.

“This is a bad look for him to be in uniform," an active duty military officer stationed at the Pentagon told the Washington Examiner. "He makes it look like the Army is behind this. Like the Army is pushing a coup."

Another officer was concerned that Vindman’s testimony veered too much into personal assessment. “I don't care what he thinks, he's entitled to his opinion," the officer said. "But it's an opinion and he should give it without the uniform."

A third officer said that Vindman's weight indicated he would be unlikely to pass the Combat Fitness Test even though he had achieved a Ranger tab earlier in his career.

Matt Zeller, an Afghanistan veteran and fellow at the American Security Project, defended Vindman. “I think he’s a patriot, and how he’s been treated is an abomination,” Zeller told the Washington Examiner. “All he is is a public servant doing his duty.”

Vindman might have been required to wear his uniform, Zeller said, although where Army regulations come down on the issue is unclear. The Army's Training and Doctrine Command did not respond to questions from the Washington Examiner.

H.R. McMaster, who was an active duty lieutenant general in the Army during his tenure as national security adviser, did not normally wear his uniform at the White House.

Military personnel such as Vindman detailed to the NSC operate within a unique system. Unlike other troops who report to military commanders, military NSC staffers fall under directors within the NSC itself. As a Ukraine expert, Vindman reports to civilian Andrew Peek, who replaced Tim Morrison as the NSC’s senior director for European and Russian affairs after Morrison announced his departure last Wednesday, one day before he testified before the House impeachment proceeding.

Military detailees generally are assigned to a unit within the Department of Defense for administrative issues such as leave and pay. Performance reports, however, are handled by the individual’s boss on the NSC.

Most NSC staffers are drawn from the military and various other government agencies. They generally are recruited via word-of-mouth, another change from typical government agencies that are notorious for their long application processes.

The Reagan administration’s NSC included Lt. Gen. Colin Powell and Lt. Col. Oliver North, . Powell was national security adviser from 1987 to 1989 and went on to become chairman of the Joint Chiefs of Staff and Secretary of State . North was on the NSC from 1981 to 1986 and testified in uniform during the Iran-Contra hearings.