20 years since 9/11: Defining images from two decades of the 'war on terror'

The second tower of the World Trade Center explodes into flames after being hit by an airplane in New York, September 11, 2001. REUTERS/Sara K. Schwittek

President George W. Bush listens as White House Chief of Staff Andrew Card informs him of a second plane hitting the World Trade Center while Bush was conducting a reading seminar at the Emma E. Booker Elementary School in Sarasota, Florida,...more

A New York City fireman calls for more rescue workers to make their way into the rubble of the World Trade Center, September 15, 2001. REUTERS/U.S. Navy/Journalist 1st Class Preston Keres

Investigators head into the debris field at the site of a commercial plane crash near Shanksville, Pennsylvania, September 11, 2001. REUTERS/Jason Cohn

The damaged area of the Pentagon building, where a commercial jetliner slammed into it September 11, is seen in the early morning at sunrise with the U.S. Capitol Building in the background, September 16, 2001. REUTERS/Larry Downing

Then-President George W. Bush is shown with retired firefighter Bob Beckwith (R) at the scene of the World Trade Center disaster, September 14, 2001. REUTERS/Win McNamee

A US Air Force B-52 flies over after releasing its bombs on front line Taliban positions near Bagram airport, some 30kms north of Kabul, November 8, 2001. REUTERS/Yannis Behrakis

Anti-Taliban Afghan fighters watch several explosions from U.S. bombings in the Tora Bora mountains in Afghanistan, December 16, 2001. REUTERS/Erik de Castro

A young Afghan woman shows her face in public for the first time after 5 years of Taliban Sharia law as she waits at a food distribution center in central Kabul, November 14, 2001. REUTERS/Yannis Behrakis

A group of U.S. Marines of the 15th MEU (Marine Expeditionary Unity) move out to take a position in the desert outside their forward base in southern Afghanistan, November 29, 2001. REUTERS/Jim Hollander

U.S. Marines from Charlie 1/1 of the 15th MEU (Marine Expeditionary Unit) fill sand bags around their light mortar position on the front lines of southern Afghanistan, December 2001. REUTERS/Jim Hollander

The body of CIA officer Johnny Mike Spann is carried by a Marine honor guard from an Air Force aircraft at Andrews Air Force Base, December 2, 2001. Spann was the first known American combat death in the U.S. military campaign in Afghanistan. ...more

U.S. Marines, shown through a night vision scope, escort battlefield detainees into a detention center at the Kandahar International Airport, December 18, 2001. REUTERS/USMC-Thomas Michael Corcoran

An Afghan girl reads from the board in a home-based school in Kabul, December 2, 2001. The school, operating secretly for a year under the strict Taliban regime, has now opened its doors for all children ready to pay a small monthly fee. ...more

U.S. Army 10th Mountain Division soldier Jorge Avino from Miami, Florida carves the body count their mortar team has chalked up on a rock, near the villages of Sherkhankheyl, Marzak and Bobelkiel, in Afghanistan, March 9, 2002. REUTERS/POOL/Joe...more

British soldiers serving with ISAF forces (International Security Assistance Force) in Kabul surround a beacon lit in honor of the Queen's Golden Jubilee, June 3, 2002. REUTERS/Caren Firouz

More than 500 Sailors and Marines assemble on the flight deck of the USS Belleau Wood to commemorate the one-year anniversary of the September 11 attacks by spelling out the quote from Todd Beamer, a passenger on United Flight 93, which crashed in...more

U.S. President George W. Bush addresses U.S. Army soldiers and their families at Fort Hood, Texas, January 3, 2003. Bush addressed the possiblity of military action against Iraq. REUTERS/Jeff Mitchell

An explosion rocks Baghdad during air strikes unleashed by U.S.-led forces, March 21, 2003. REUTERS/Goran Tomasevic

U.S. Navy Hospital Corpsman HM1 Richard Barnett, 41, a medic with the 1st Marine Division, 1st Regimental Combat Team, 3rd Battalion, holds an Iraqi boy in central Iraq, March 29, 2003. REUTERS/Damir Sagolj

U.S. Marine Corp Assaultman Kirk Dalrymple watches as a statue of Iraq's President Saddam Hussein falls in central Baghdad, April 9, 2003. REUTERS/Goran Tomasevic

A British army officer holds her handgun cocked as Iraqi civilians flee fighting in Basra, Iraq, April 6, 2003. REUTERS/Yannis Behrakis

Corporal Clifford Thompson from Clebourne, Texas, of HHC 4th Infantry Divsion of the U.S. Army looks through the window of his humvee in Tikrit, which was damaged by an IED on their way to Tikrit from Baghdad, September 19, 2003. REUTERS/Arko...more

An Iraqi girl sits outside as U.S. soldiers of 720 Military Police Battalion of the Fourth Division search her house during a joint raid with the Iraqi police on a tiny settlement north of Tikrit, September 14, 2003. REUTERS/Arko Datta

Iraqis celebrate on a downed U.S. Apache military helicopter in the Hindiya district, southwest of Baghdad, March 24, 2003. REUTERS/Faleh Kheiber

A row of U.S. Army helmets are perched on M-16 rifles during a memorial at Al Asad air base for the 15 victims of a Chinook helicopter which was shot down by insurgents, November 6, 2003. REUTERS/Chris Helgren

A detained Iraqi man with a plastic bag covering his head sits in garden of a house searched by U.S. soldiers during a night raid in Tikrit, October 30, 2003. Soldiers of the U.S. Army's 4th Infantry Division raided several houses in Tikrit looking...more

U.S. Marines kick in a door while securing a building next to the main hospital in central Baghdad, which will be used as a temporary Iraqi police headquarters, April 15, 2003. REUTERS/Jerry Lampen

An Iraqi man suspected of having explosives in his car is held after being arrested by the U.S Army near Baquba, Iraq, October 15, 2005. REUTERS/Jorge Silva

U.S. President George W. Bush delivers a speech to crew aboard the aircraft carrier USS Abraham Lincoln, as the carrier steamed toward San Diego, California, May 1, 2003. REUTERS/Larry Downing

A U.S. Army soldier speaks with a comrade as they drive to a military hospital following a grenade attack in Baghdad, July 28, 2003. REUTERS/Stefano Rellandini

An Iraqi girl holds her hands up while U.S. and Iraqi soldiers search her family house in Baquba, June 30, 2007.   REUTERS/Goran Tomasevic

An Iraqi man holds the body of a boy after a car bomb explosion at a market in the neighborhood known as New Baghdad, southeast of Baghdad, February 18, 2007.  REUTERS/Carlos Barria

An Iraqi bystander lies dead in a pool of blood, killed by U.S. soldiers who opened fire following a rocket-propelled grenade attack on a U.S. Humvee, in Baghdad, August 7, 2003. REUTERS/Oleg Popov

Saddam Hussein is filmed after his capture in footage released December 14, 2003. REUTERS/Handout

Under a sign jokingly charging $100 per visit, Sgt Ramirez Ricardo, a soldier with the Fourth Infantry division, poses in the spider hole in which Saddam Hussein was found hiding when he was captured by U.S. troops near Tikrit, December 21,...more

An Iraqi detainee gestures toward U.S. soldiers through the bars of his cell at Abu Ghraib prison outside Baghdad, May 17, 2004. REUTERS/Damir Sagolj

An Iraqi youth stalks a U.S. Army Abrams tank in the Baghdad suburb of Abu Ghraib, April 8, 2004. REUTERS/Ali Jasim

A Spanish police officer stands next to a victim as he looks out of the door of a train which was bombed outside the main train station in Madrid, Spain, March 11, 2004. An investigation by the Spanish judiciary determined the bombing was directed by...more

Mays, a young Iraqi Shi'ite girl, cries after a mortar shell which landed outside the family's home in a Najaf residential area injured her uncle, August 18, 2004. REUTERS/Ali Jasim

A British soldier jumps from a burning tank which was set ablaze after a shooting incident in the southern Iraqi city of Basra, September 19, 2005. Angry crowds attacked a British tank with petrol bombs and rocks after Iraqi authorities said they had...more

A bloodied insurgent sits blindfolded in an Iraqi police station after being captured during a morning battle in the southwestern Al-Bayaa district of Baghdad, June 20, 2005. REUTERS/Ali Jasim

British Prime Minister Tony Blair stands on the steps in Gleneagles, Scotland, after hearing the news of the explosions in London, July 7, 2005. Four blasts ripped through London during rush hour on a Thursday morning, killing 52 people and...more

The number 30 double-decker bus in Tavistock Square in central London after a bombing attack of four blasts that tore through three underground trains and the bus, July 8, 2005. REUTERS/Dylan Martinez

Kristin Kenny of Edison New Jersey clutches the grave stone of her boyfriend Dennis Flanagan at Arlington National Cemetery in Arlington, Virginia, May 25, 2006. Flanagan was killed in Iraq on January 21, 2006 by an improvised explosive device.   ...more

A photo reviewed by U.S. military officials shows detainees reading the Koran inside the grounds of the medium security portion of Camp Delta detention center at the Guantanamo Bay U.S. Naval Base in Cuba, April 6, 2006.      REUTERS/Brennan...more

A man runs down a street warning people to flee shortly after a twin car bomb attack at Shorja market in Baghdad, as Iraqis marked the first anniversary of a Shi'ite shrine bombing that pitched the country to the brink of civil war, February 12,...more

A wounded Canadian soldier from the NATO-led coalition crawls for cover seconds after his position was hit by a Taliban shell fired from an 82-millimeter recoilless rifle during an ambush in the Zhari district of Kandahar province, southern...more

A U.S. soldier with 2nd Platoon, G Company, 3rd Squadron 2nd Striker Cavalry Regiment is reflected in a mirror as he searches a house during a patrol in Baghdad, November 10, 2007.   REUTERS/Stefano Rellandini

An Iraqi man holds the body of a boy after a car bomb explosion at a market in the neighborhood known as New Baghdad, southeast of Baghdad, February 18, 2007. Two car bombs tore through a busy shopping area of a mainly Shi'ite district of Baghdad,...more

U.S. soldiers push the car of an Iraqi man to start the engine at a check point in north Baghdad, June 13, 2007.    REUTERS/Goran Tomasevic

An Iraqi man unbuttons his shirt as U.S. soldiers point their laser sights on him during an operation near the Baiji oil refinery, December 24, 2007. REUTERS/Bob Strong

Sgt. William Olas Bee, a U.S. Marine from the 24th Marine Expeditionary Unit, has a close call after Taliban fighters opened fire near Garmsir in Helmand Province of Afghanistan, May 18, 2008. REUTERS/Goran Tomasevic

A U.S. Army cadet reads a book entitled "Kill Bin Laden" as he waits with other cadets for President Barack Obama to deliver an address on U.S. policy and the war in Afghanistan at the U.S. Military Academy in West Point, New York, December 1, 2009....more

U.S. SPC Henry Rosenquist of 2-12 Infantry 4BCT-4ID Task Force Mountain Warrior sits in the computer room in Honaker Miracle camp at the Pesh valley of Kunar Province, August 13, 2009. REUTERS/Carlos Barria

Afghan children look at Canadian soldiers of the NATO-led coalition while they patrol in their compound in the Taliban stronghold of Zhari district in Kandahar province, southern Afghanistan, March 19, 2009. REUTERS/Stefano Rellandini

Laura Youngblood, widow of U.S. Navy Petty Officer Travis L. Youngblood, touches his gravestone in Section 60 of Arlington National Cemetery during the Memorial Day weekend in Arlington, Virginia, May 24, 2009. Youngblood died of wounds received in...more

A U.S. soldier of 2-12 Infantry 4BCT-4ID Task Force Mountain Warrior takes a break during a night mission near Honaker Miracle camp at the Pesh valley of Kunar Province, Afghanistan, August 12, 2009. REUTERS/Carlos Barria

A U.S. Army medevac crew member attempts to revive a Marine mortally wounded in an IED blast near the town of Marjah in Helmand province, Afghanistan, August 22, 2010. REUTERS/Bob Strong

A young girl stands with other mourners as the hearses carrying the coffins of five British soldiers are driven through the streets of Wootton Bassett, in southern England, February 18, 2010. Lance Sergeant Dave Greenhalgh, L/Cpl Darren Hicks,...more

U.S. Marine Lance Corporal Chris Sanderson, 24, from Flemington, New Jersey shouts as he tries to protect an Afghan man and his child after Taliban fighters opened fire in the town of Marjah, in Nad Ali district, Helmand province, February 13, 2010. ...more

U.S. Army soldiers from the 2nd Platoon, B battery 2-8 field artillery, fire a howitzer artillery piece at Seprwan Ghar forward fire base in Panjwai district, Kandahar province southern Afghanistan, June 12, 2011. REUTERS/Baz Ratner

U.S. President Barack Obama and Vice President Joe Biden, along with members of the national security team, receive an update on the mission against Osama bin Laden in the Situation Room of the White House, May 1, 2011. Also pictured are Secretary of...more

The compound, within which al Qaeda leader Osama bin Laden was killed, is seen in flames after it was attacked in Abbottabad, Pakistan, May 2, 2011. REUTERS/Stringer

Revelers cheer outside the White House in Washington after President Barack Obama announced live on television the death of Osama bin Laden. Bin Laden, May 1, 2011. REUTERS/Jason Reed

A plane flies through the "Tribute in Lights" in Lower Manhattan in New York ahead of the tenth anniversary of the 9/11 attacks, September 10, 2011. REUTERS/Eric Thayer

U.S. Air Force Major Stacie Shafran carries her luggage to a loading paddock while waiting for her departure from Iraq at the former U.S. Sather Air Base near Baghdad, Iraq, December 14, 2011.  REUTERS/Shannon Stapleton

U.S. Mine Resistant Ambush Protected (MRAP) vehicles drive through Camp Adder before departing what is now known as Imam Ali Base near Nasiriyah, Iraq, December 16, 2011. The last convoy of U.S. soldiers pulled out of Iraq, ending their withdrawal...more

Boot prints of U.S. soldiers are seen at the nearly deserted Camp Adder, now known as Imam Ali Base, near Nasiriyah, Iraq, December 16, 2011. REUTERS/Mario Tama/Pool

Vehicles belonging to forces loyal to Libyan leader Muammar Gaddafi explode after an airstrike by coalition forces, along a road between Benghazi and Ajdabiyah, March 20, 2011. REUTERS/Goran Tomasevic

A protester reacts as the U.S. Consulate in Benghazi is seen in flames, September 11, 2012. REUTERS/Esam Al-Fetori

Lesleigh Coyer, 25, of Saginaw, Michigan, lies down in front of the grave of her brother, Ryan Coyer, who served with the U.S. Army in both Iraq and Afghanistan, at Arlington National Cemetery in Virginia, March 11, 2013. Coyer died of complications...more

A U.S. Army soldier with Charlie Company, 36th Infantry Regiment, 1st Armored Division blows a bubble with his chewing gum during a mission near Command Outpost Pa'in Kalay in Maiwand District, Kandahar Province, February 3, 2013. REUTERS/Andrew...more

An explosion is seen during a car bomb attack at a Shi'ite political organization's rally in Baghdad, April 25, 2014. REUTERS/Thaier al-Sudani

U.S. troops from the Nato-led International Security Assistance Force (ISAF) light candles during Christmas Eve celebrations at Bagram Airfield, north of Kabul, December 24, 2014. REUTERS/Mohammad Ismail

Militant Islamic State fighters take part in a military parade along the streets of northern Raqqa province in Syria, June 30, 2014. Militant Islamist fighters held a parade in Syria's northern Raqqa province to celebrate their declaration of an...more

A female member of the Kurdish People's Protection Units (YPG) mourns over the grave of her fellow fighter, who was killed during clashes with the al Qaeda-affiliated Islamic State of Iraq and the Levant, in Ras al-Ain, Syria, January 28, 2014....more

Smoke rises over the Syrian town of Kobani after a U.S.-led airstrike, as seen from the Mursitpinar border crossing on the Turkish-Syrian border in the southeastern town of Suruc in Sanliurfa province, October 18, 2014. The U.S.-led coalition has...more

Members of the Iraqi Special Operations Forces take their positions during clashes with the al Qaeda-linked Islamic State of Iraq and the Levant, in the Iraqi city of Ramadi, June 19, 2014. REUTERS/Stringer

Displaced people from the minority Yazidi sect, fleeing violence from forces loyal to the Islamic State in Sinjar town, walk towards the Syrian border, on the outskirts of Sinjar mountain, near the Syrian border town of Elierbeh of Al-Hasakah...more

French fire brigade members aid an injured individual near the Bataclan concert hall following fatal shootings in Paris, France, November 13, 2015. At least 130 people were killed in the attacks in Paris which Islamic State of Iraq and the Levant...more

Islamic State militants lead what are said to be Ethiopian Christians along a beach in Wilayat Barqa, in this image from an undated video released on social media on April 19, 2015. The video appeared to show militants shooting and beheading about 30...more

A body is seen on the ground after 86 people were killed in Nice, France, when a truck ran into a crowd celebrating the Bastille Day national holiday, July 15, 2016. The Islamic State claimed responsibility for the attack.  REUTERS/Eric Gaillard

A man cries as he carries his daughter while walking from an Islamic State-controlled part of Mosul towards Iraqi special forces soldiers during a battle in Mosul, Iraq, March 4, 2017. REUTERS/Goran Tomasevic

An Iraqi special forces soldier shot dead an Islamic State suicide bomber in Mosul, Iraq, March 3, 2017. REUTERS/Goran Tomasevic

A Syrian Democratic Forces (SDF) fighter sits as medics treat his comrades injured by sniper fire from Islamic State militants, in a field hospital in Raqqa, Syria, June 28, 2017. REUTERS/Goran Tomasevic

A member of the Syrian Democratic Forces calls his comrades during fighting with Islamic State fighters in Raqqa, Syria, August 14, 2017. REUTERS/Zohra Bensemra

A boy waits with his mother as they queue with others for humanitarian and medical help after leaving Baghouz, the last stronghold of the Islamic State caliphate, in Deir Al Zor, Syria, March 5, 2019. REUTERS/Rodi Said

A convoy of U.S. vehicles is seen after withdrawing from northern Syria, in Erbil, Iraq, October 21, 2019. REUTERS/Azad Lashkari

A baby is handed over to U.S. soldiers over the perimeter wall of the airport for it to be evacuated, in Kabul, Afghanistan, August 19, 2021. Omar Haidari/via REUTERS

A U.S. Air Force aircrew prepare for qualified evacuees to board a U.S. Air Force C-17 Globemaster III aircraft in support of the Afghanistan evacuation at Hamid Karzai International Airport, Afghanistan, August 21, 2021.  U.S. Air Force/Senior...more

Evacuees crowd the interior of a U.S. Air Force C-17 Globemaster III transport aircraft, carrying some 640 Afghans to Qatar from Kabul, August 15, 2021. U.S. Air Force/Air Mobility Command Public Affairs.

U.S. President Joe Biden salutes during the dignified transfer of the remains of military service members who were killed by a suicide bombing at the Hamid Karzai International Airport, at Dover Air Force Base in Dover, Delaware, August 29, 2021. ...more

Carrying his rifle down by his side, Major General Chris Donahue, commander of the storied 82nd Airborne Division, became the last U.S. soldier to board the final flight out of Afghanistan a minute before midnight on August 30, 2021.  XVIII...more

An American flag and red rose stand in the names of those lost at the edge of the south reflecting pool of the 9/11 Memorial & Museum ahead of the 20th anniversary of the 9/11 attacks in Lower Manhattan in New York City, September 8, 2021. ...more