Gian P. Gentile is a colonel in the United States Army, who is on the faculty of the United States Military Academy at West Point. He served two combat tours in the Iraq War, the second as commander of 8/10 Reconnaissance Squadron operating against insurgents in Baghdad in 2006, and is a highly visible critic of counterinsurgency doctrine. He also questions the ability of the United States to exert change through preventive war.
Andrew Bacevich has called him a leader of the "Conservative" versus "Crusader" faction in current military thinking, which challenges the "revisionist" interpretation that the Vietnam War could have been won, if only the U.S. had used a proper counterinsurgency approach. Bacevich describes Gentile's core concern as "an infatuation with stability operations will lead the Army to reinvent itself as 'a constabulary,' adept perhaps at nation-building but shorn of adequate capacity for conventional war-fighting." He is an advocate of the principles of the Weinberger-Powell Doctrine, as seen in the Gulf War.
COL Gentile points to GEN Creighton Abrams, the last U.S. combat commander in the the Vietnam War, deciding, immediately after that war, to prepare the Army for combat with the Soviet Union, rather than a less understood counterinsurgency. "If Abrams had chosen otherwise, would the ground phase of the 1991 Gulf War have been completed in four days? Would the 2003 drive to Baghdad have been accomplished in three weeks?"If the Army principally prepares itself for counterinsurgency, as did the Israeli Defense Forces manning checkpoints in the Occupied Territories in the early 2000s, it
...could easily reprise Israel’s experience in southern Lebanon two years ago. Because the Israel Defense Forces (IDF) had devoted themselves nearly exclusively to low-intensity conflict in the West Bank and Gaza, their conventional warfighting skills atrophied to the point where they could not fight effectively against a semi-conventional foe in Lebanon, according to U.S. Army historian Matt Matthews, relying heavily on the Israeli Winograd Commission that studied the reasons for the IDF's disastrous showing
In an article entitled "Our COIN doctrine removes the enemy from the essence of war", he challenges what he considers the prevailing thinking that the Army of the future should prepare principally for asymmetrical counterinsurgency, rather than decisive large-scale combat. 
In January 2009, he wrote an article that says "absolutely not" to the claim that the United States is still too focused on conventional warfare.  Andrew Exum, of the Center for a New American Security, writing in his Abu Muqawama blog, partially challenges Gentile's arguments.  Exum, argues that while the Army may indeed have focused more on counterinsurgency, the United States Navy and United States Air Force still have strong conventional capability. Gentile entered cheerfully into the blog discussion, responding "If I had been more careful I would have asked the editors to replace "military" with Army. You are correct that the AF and Navy are not focused on Coin; NOR BY JOBSHOULD THEY BE. They need to keep nukes up and ready, the sea lanes open for commerce, command of the air, etc. So cut me a break on this one because my response was tied discretely to the Army and in that sense I don’t see how you can argue otherwise."
Dude, AM [Abu Muqawama, Exum's blog name], brother in arms, please stop calling me anti-COIN [counterinsurgency]. Dave D[ilegge] at SWJ Small Wars Journal loves to apply that moniker to me; but it is not true. I am not anti-coin and if you have read any of my stuff you will see how over and over again I call for the Army to maintain, institutionalize what we have learned from COIN over the past seven years. I have also said over and over again that the army does need a COIN capability in the future. However, we should not transform the army to a force built primarily for COIN and irregular war
Gentile does, in Small Wars Journal, argue about the approach to Afghanistan, citing recent reports that the enemy has gained the initiatives, and arguing that an overly population-centric counterinsurgency model leads to stagnation of warfighting skills. 
He wrote, in a New York Times op-ed, that the major differences between 2006 and 2007 were:
- "a decision by senior American leaders in 2007 to pay large amounts of money to Sunni insurgents to stop attacking Americans and join the fight against al-Qaeda.
- the decision by the Shiite militia leader, Moqtada al-Sadr, to refrain from attacking coalition forces
- the separation of rival factions in Baghdad stemming from sectarian cleansing in 2006-2007
Bacevich writes that Gentile's criticism of John Nagl is a proxy for criticism of George W. Bush Administration policymakers such as Dick Cheney, Donald Rumsfeld, and Paul Wolfowitz; that they are the real target when Gentile speaks of Nagl's “breathtaking” assumption about “the efficacy of American military power to shape events” expresses a larger dissatisfaction with similar assumptions held by the senior officials who concocted the Iraq War in the first place. 
Earlier Army assignments
He commanded a tank company in Korea from 1993 to 1995, taught history at West Point, and served as a division planner and cavalry squadron executive officer. He again taught history before going to his first tour in Iraq.
- B.A., History, University of California, Berkeley, 1986
- M.M.A.S., School of Advanced Military Studies, Command and General Staff College 2000
- PhD., History, Stanford University, 2000
- Andrew Bacevich (October 2008), "The Petraeus Doctrine", Atlantic Monthly
- Gian P. Gentile (Summer 2008), "A (Slightly) Better War: A Narrative and Its Defects", World Affairs
- Gian P. Gentile (January 2008), "Our COIN doctrine removes the enemy from the essence of war", Armed Forces Journal
- Gian P. Gentile (January 2009), "Think Again: Counterinsurgency", Foreign Policy (magazine)
- Andrew Exum (15 January 2009), "Gian Gentile versus Abu Muqawama, Round 582", Abu Muqawama
- Gian P. Gentile (2 September 2009), "Gaining the Initiative in Afghanistan", Small Wars Journal
- Gian P. Gentile (4 February 2008), "Our troops did not fail in 2006", New York Times