Question: How many tours in the Iraq War did the author of the autobiography American Sniper do ?

Context paragraphs:
Refugees of Iraq: Refugees of Iraq are Iraqi nationals who have fled Iraq due to war or persecution.  Throughout the past 30 years, there have been a growing number of refugees fleeing Iraq and settling throughout the world, peaking recently with the latest Iraq War.  Precipitated by a series of conflicts including the Kurdish rebellions during the Iran–Iraq War (1980 to 1988), Iraq's Invasion of Kuwait (1990) and the Gulf War (1991), the subsequent sanctions against Iraq, and culminating in the violence during and after the American-led invasion and occupation of Iraq, millions have been forced by insecurity to flee their homes in Iraq.  Unlike most refugees, Iraqi refugees have established themselves in urban areas in other countries rather than in refugee camps.  In April 2007, there was an estimate of over 4 million Iraqi refugees around the world, including 1.9 million in Iraq, 2 million in neighboring Middle East countries, and around 200,000 in countries outside the Middle East.  The United Nations High Commissioner for Refugees (UNHCR) has led the humanitarian efforts for Iraqi refugees.  The Iraqi displacement of several million is the largest in the Middle East, and is much larger than the number of Palestinians who were displaced in 1948 during the creation of the state of Israel.

American Sniper: American Sniper is a 2014 American biographical war drama film directed by Clint Eastwood and written by Jason Hall.  It is loosely based on the memoir "American Sniper: The Autobiography of the Most Lethal Sniper in U.S. Military History" (2012) by Chris Kyle, with Scott McEwen and Jim DeFelice.  The film follows the life of Kyle, who became the deadliest marksman in U.S. military history with 255 kills from four tours in the Iraq War, 160 of which were officially confirmed by the Department of Defense.  While Kyle was celebrated for his military successes, his tours of duty took a heavy toll on his personal and family life.  The film was produced by Eastwood, Robert Lorenz, Andrew Lazar, Bradley Cooper, and Peter Morgan.  It stars Cooper as Kyle and Sienna Miller as his wife Taya, with Luke Grimes, Jake McDorman, Cory Hardrict, Kevin Lacz, Navid Negahban, and Keir O'Donnell in supporting roles.

French support for Iraq during the Iran–Iraq war: French support for Iraq during the Iran–Iraq war was an important element to strengthen Iraq for the Iran–Iraq war.  Starting in roughly 1975, leading up to the Iran–Iraq War, as well as the war itself, the greatest amount of military equipment came to Iraq from the Soviet Union, but France was probably second, and generally provided higher-technology equipment than the Soviets.

American Sniper (book): American Sniper: The Autobiography of the Most Lethal Sniper in U.S. Military History is an autobiography by United States Navy SEAL Chris Kyle, written with Scott McEwen and Jim DeFelice.  With 255 kills, 160 of them officially confirmed by the Pentagon, Kyle is the deadliest marksman in U.S. military history.  The book was published by William Morrow and Company on January 2, 2012 and appeared on "The New York Times" Best Seller list for 37 weeks.

Iraq War documents leak: The Iraq War documents leak is the disclosure to WikiLeaks of 391,832 United States Army field reports, also called the Iraq War Logs, of the Iraq War from 2004 to 2009 and published on the Internet on 22 October 2010.  The files record 66,081 civilian deaths out of 109,000 recorded deaths.  The leak resulted in the Iraq Body Count project adding 15,000 civilian deaths to their count, bringing their total to over 150,000, with roughly 80% of those civilians.  It is the biggest leak in the military history of the United States, surpassing the Afghan War documents leak of 25 July 2010.

Chris Kyle: Christopher Scott "Chris" Kyle (April 8, 1974 – February 2, 2013) was a United States Navy SEAL veteran and sniper.  Kyle served four tours in the Iraq War and was awarded several commendations for acts of heroism and meritorious service in combat.  He was awarded one Silver Star Medal, four Bronze Star Medals with "V" devices, a Navy and Marine Corps Achievement Medal and numerous other unit and personal awards.

Walt Martin: Walt Martin (April 8, 1945 – July 24, 2014) was an American production sound mixer.  He was nominated for Academy Awards in the category Best Sound for the 2006 film "Flags of Our Fathers" and the 2014 film "American Sniper".  He worked on more than 70 films.  He died of vasculitis on July 24, 2014, aged 69.  His final film, "American Sniper", was released posthumously.

Canada and Iraq War resisters: During the Iraq War, which began with the 2003 invasion of Iraq, there were United States military personnel who refused to participate, or continue to participate, in that specific war.  Their refusal meant that they faced the possibility of punishment in the United States according to Article 85 of the US Uniform Code of Military Justice.  For that reason some of them chose to go to Canada as a place of refuge.  The choice of these US Iraq war resisters to go to Canada has led to considerable debate in Canada's society, press, legal arenas, and political arenas.  Much of the debate on this issue has been due to the controversial nature of the Iraq War itself.  Among the many elements of that debate are Canada's relationship to the Iraq war, and Canada's relationship to the US, its largest trading partner.

Iraq–Pakistan relations: Iraq–Pakistan relations refers to the foreign relations between the Republic of Iraq and the Islamic Republic of Pakistan.  In 1955 Iraq and Pakistan joined the Baghdad Pact, a military alliance against the Soviet Union.  However, when the king of Iraq was assassinated in 1958, Iraq pulled out of the Baghdad Pact, which was renamed as the Central Treaty Organization.  Tensions persisted between Iraq and Pakistan through the late twentieth and early twenty-first centuries with the Iran–Iraq War, the Gulf War, and the Iraq War.  However the relations stabilized.  Pakistan currently maintains an embassy in Baghdad and Iraq in Islamabad.

Kevin Lacz: Kevin “Dauber” Lacz is a United States Navy SEAL veteran who served two tours in the Iraq War with SEAL Team 3.  His platoon's 2006 deployment to Ramadi has been discussed in several books, including Dick Couch’s "The Sheriff of Ramadi", Jim DeFelice’s "Code Name: Johnny Walker", and Chris Kyle's New York Times best-selling autobiography, "American Sniper".  Lacz’s presence in the book led to his involvement in the production of and eventual casting in the Clint Eastwood-directed Oscar-winning biopic of the same name (starring Bradley Cooper).

Supporting paragraphs: Kevin Lacz Chris Kyle
Answer: four