Six Democratic lawmakers released a video in November reminding the men and women of the military of their duty to refuse any illegal order. Although all of them have been contacted by Trump's Department of Justice or Pentagon as part of an investigation, one of them, Senator Mark Kelly, is also a target of the Defense Department. Sen. Kelly is suing Pete Hegseth over the matter. 

“It is a very fine line, but it's a special obligation that public servants carry, particularly those in uniform, to follow through in this manner and to do so in a way that they understand precisely why what they're being asked to do is lawful in prosecuting the national interest of the United States,” says Sean O'Keefe, University Professor Emeritus and former NASA administrator.

“Every military officer and for that matter, every public servant, when you tak the oath of office...that you in turn have an obligation to be absolutely straightforward abut carrying out the objectives of the order issued,” O'Keefe says.

“You have to have the confidence that the senior leadership is issuing lawful orders. And as a situation where, if there is any ambiguity, ask. And what these members of Congress were inviting, having been there and having done that, having been in those positions where if there was ever any question in their mind, they worked within a culture in which you could pose that question,” says O'Keefe.

Watch the full MS NOW interview here.