President Donald Trump's new national security adviser hasn't just advocated speaking truth to power — he wrote the book on it.
The selection Monday of Army Lt. Gen. H.R. McMaster is earning Trump rare praise from both sides of the political aisle for promoting a "brilliant strategist" who showed fortitude on the battlefield during both Iraq wars.
It was McMaster's 1997 book "Dereliction of Duty," a searing indictment of top military brass, that became a must-read for young officers. In it, he rebukes senior leadership during the Vietnam War for having cowered to the White House's political agenda.
More from NBC News:
Veteran CIA analyst quits agency over Trump's intel moves, criticism
Trump names Lt. Gen. H.R. McMaster as new national security adviser
Michael Flynn resigns as national security adviser over talks with Russia
"The war in Vietnam was not lost in the field, nor was it lost on the front pages of the New York Times or the college campuses," he wrote. "It was lost in Washington, D.C."
McMaster, 54, intends to remain on active duty while he serves on Trump's senior team. He told reporters in brief remarks Monday that he "looks forward to joining the national security team and doing everything I can to advance and protect the interests of the American people."
Having fought on the ground in Iraq in 1991, McMaster will now be tasked with helping to end the fighting in that country, which remains ravaged by ISIS.
McMaster joins two retired generals — Defense Secretary Jim Mattis and Homeland Security Secretary John Kelly — already in Trump's inner circle, adding to the impression that the president prefers military men in top roles.
He is filling the brief tenure of Mike Flynn, who abruptly resigned as national security adviser last week after it was revealed he misled Vice President Mike Pence and other White House officials about communications with a Russian ambassador.