President Trump has named Army Lt. Gen. Herbert Raymond McMaster as his new national security adviser.
McMaster is replacing Michael Flynn, a retired lieutenant general, who recently resigned as Trump's first national security adviser.
Trump's decision to have McMaster help manage the National Security Council and be his chief adviser on national security matters has received widespread praise from across the political spectrum. McMaster, a decorated combat veteran, is seen as an intellectual who is not afraid to question authority.
In 1997, McMaster wrote his book Dereliction of Duty, which criticizes the United States' military and political leadership for the failures of the Vietnam War.
McMaster is a West Point graduate with a Ph.D. in U.S. history from the University of North Carolina at Chapel Hill.
Here are 13 of McMaster's best quotes:
1. "It's so damn complex. If you ever think you have the solution to this, you're wrong and you're dangerous."
(Dereliction of Duty)
2. "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. It was lost in Washington, D.C."
(Dereliction of Duty)
3. "The warrior ethos is at risk because popular culture waters down and coarsens the warrior ethos. Warriors are most often portrayed as fragile traumatized human beings. Hollywood tells us little about the warrior's calling or commitment to his or her fellow warriors or what compels him or her to act courageously, endure hardships, take risks, or make sacrifices."
(November 2014 keynote address at Georgetown University Veteran's Day ceremony)
4. "Combined arms is basically a game of rock, paper, scissors. If you show up to combat with a rock, the enemy may have paper, but then you have scissors ready to go."
(July 2014 interview with the Ledger-Enquirer)
5. "The requirement to adapt quickly to unforeseen conditions means that commanders will need additional forces and resources that can be committed with little notice. For efficiency in all forms of warfare, including counterinsurgency, means barely winning. And in war, barely winning can be an ugly proposition."
(Winter 2009 article penned by McMaster in World Affairs)
6. "Some problems in the world are not bullet-izable."
(2010 quote given to the New York Times)
7. "There is a tendency in the United States to confuse the study of war and warfare with militarism. Thinking clearly about the problem of war and warfare, however, is both an unfortunate necessity and the best way to prevent it."
(Veteran's Day speech, 2014)
8. "As previous generations defeated Nazi fascism, Japanese imperialism, and communist totalitarianism and oppression, we will defeat these enemies who cynically use a perverted interpretation of religion to incite hatred and violence."
(Veteran's Day speech, 2014)
9. "If we show up somewhere with U.S. Army on our chest, in large numbers, there's not going to be a fair fight."
(Ledger-Enquirer interview, 2014)
10. "It is our soldiers, sailors, airmen, and Marines who have volunteered for military service in time of war who will continue to stand between us and these terrorists who rape women, abuse children, and commit mass murder of innocents."
(Veteran's Day speech, 2014)
11. "Our leaders can't feel compelled to tell their bosses what they want to hear."
(April 2013 interview with McKinsey & Company)
12. "The warrior ethos is at risk because fewer and fewer Americans are connected to our professional military. Separation from our society is consequential because warriors depend on respect for what they do to maintain their self-respect."
(Veteran's Day speech, 2014)
13. "The warrior ethos is at risk because some argue that victory over an enemy or winning in war is an old idea that is no longer relevant in today's complex world."
(Veteran's Day speech, 2014)