WASHINGTON (AP) — The Pentagon says it is investigating Democratic Sen. Mark Kelly of Arizona for possible breaches of military law after Kelly joined a handful of other lawmakers in a video that called for U.S. troops to refuse unlawful orders.

The Pentagon’s statement, which was posted on social media on Monday, cited a federal law that allows retired service members to be recalled to active duty on orders of the defense secretary for possible court-martial or other measures. Kelly served in the U.S. Navy as a fighter pilot before going on to become an astronaut. He retired at the rank of captain.

It is extraordinary for the Pentagon, which until the second Trump term has usually gone out of its way to act and appear apolitical, to directly threaten a sitting member of Congress with investigation.

In its statement, the Pentagon suggested that Kelly’s statements in the video interfered with the “loyalty, morale, or good order and discipline of the armed forces” by citing the federal law that prohibits such actions.

“A thorough review of these allegations has been initiated to determine further actions, which may include recall to active duty for court-martial proceedings or administrative measures,” the statement said.

In the video that was posted last Tuesday, Kelly was one of six lawmakers who served in the military or intelligence community to speak “directly to members of the military.”

Kelly told troops “you can refuse illegal orders,” and other lawmakers said they needed troops to “stand up for our laws … our Constitution.”

Defense Secretary Pete Hegseth, in a post to his personal social media account, said Kelly was the only lawmaker targeted for investigation because he is the only one who formally retired from the military and thus is still under the Pentagon’s jurisdiction.

“Kelly’s conduct brings discredit upon the armed forces and will be addressed appropriately,” Hegseth added.

Days after the video was released, President Donald Trump accused the lawmakers of sedition “punishable by DEATH” in a social media post.

Chief Pentagon spokesman Sean Parnell also released a statement, saying, “Our military follows orders, and our civilians give legal orders.”

“These politicians are out of their minds,” Parnell added.

Speaking Sunday on CBS’ “Face the Nation,” Kelly said Trump’s words were “very serious” and “carry tremendous weight.” Kelly added that “because of what he says there is now increased threats against us.”

Kelly’s office did not immediately respond Monday to a request for comment on the Pentagon investigation.

Troops, especially uniformed commanders, do have a specific obligations to reject orders that are unlawful, if they make that determination.

While commanders have military lawyers on their staffs to consult with in making such a determination, rank-and-file troops who are tasked with carrying out those orders are rarely in a similar position and often have to rely on their superiors.

Broad legal precedence also holds that just following orders, colloquially known as the “Nuremberg defense” as it was used unsuccessfully by senior Nazi officials to justify their actions under Adolf Hitler, doesn’t absolve troops.

Yet the reaction from troops to the video online has been almost nonexistent.

A former servicemember who helps run an online military forum said the lawmakers’ message from last week is unlikely even to reach troops because the video was posted only on X and was far too long to be reposted on platforms like TikTok where troops actually consume information. He spoke on condition of anonymity to speak candidly and avoid retaliation.