From October 7, 2001, until December 28, 2014, US and NATO forces carried out combat operations in Afghanistan.
While those operations were meant to end and the US had begun withdrawing troops from the country by the end of 2014, the Taliban continued success on the battlefield, coupled with the ineffective performance Afghan security forces, led the US to continue its deployment in the country, which has seen decades of wars fought by numerous combatants.
Overall, the US has a force of nearly 10,000 Afghanistan, though President Barack Obama intended to reduce that force to 5,500 in 2017, the continued Taliban threat has caused a change of plans, with some 8,400 troops slated to remain in Afghanistan at the end of next year.
Most NATO forces withdrew from Afghanistan at the end of 2014.
By the end of that year, foreign-military losses amounted to 3,500 killed and 33,000 wounded. Those loses included 2,400 dead and 20,000 wounded for the US; 453 and 7,500 for Great Britain; 159 and 1,859 for Canada; and 89 and 725 for France, though those numbers do not include private-security contractors.
Since 2001, the US has spent about $110 billion on Afghanistan's reconstruction, more than the cost of the Marshall Plan that reconstruct Europe after World War II. Washington has allocated more than $60 billion since 2002 to train and equip Afghan troops.
The US money spent in Afghanistan has yielded limited results, however.
Security in the country remains precarious and the Taliban is believed to control more territory in Afghanistan than at any time since 2001. A record 5,100 civilian casualties, including 1,600 deaths, were recorded in the first half of 2016, according to the UN.
Below, you can see a selection of photos documenting the last 15 years the US's war in Afghanistan.
The past 15 years at war in Afghanistan
The past 15 years at war in Afghanistan
The United States and Britain on October 7, 2001 launched a first wave of air strikes against Afghanistan and President George W. Bush said the action heralded a "sustained, comprehensive and relentless" campaign against terrorism. Eyewitnesses said they saw flashes and heard explosions over the Afghan capital of Kabul in the first phase of what the United States has said will be a protracted and wide-ranging war against terrorism and the states that support it. The attack had been prepared since the September 11 suicide attacks on the United States that killed around 5,600 people. A U.S. Air force B-52 bomber drops a load of M117 750-pound bombs over a bombing range in the United States in this undated file photo.B-52s, B-1 and B-2 stealth bombers are some of the aircraft that were reportedly used in the attacks on Afghanistan. REUTERS/USAF-Handout KM/HB
Two Northern Alliance soldiers watch as the dust and smoke rises after
explosions in Taliban positions on Kalakata hill, near the village of
Ai-Khanum in northern Afghanistan, November 1, 2001. The Pentagon said
on Wednesday B-52s dropped heavy loads of bombs, a tactic known as
carpet bombing, on Taliban troops north of Kabul as a result of
improved tergeting intelligence, partly from U.S. special forces on the
ground. REUTERS/Vasily Fedosenko
U.S. Marine PV2 Eileen M. Schnetzko stands on guard at Bagram airport,
March 2, 2002. U.S. troops are based at Bagram, north of Kabul. There
are some 4,000 U.S. troops based in Afghanistan as part of the
international war against terrorism. REUTERS/Mario Laporta REUTERS
A U.S. special forces soldier (L) watches while Afghan militia wait in
line to turn in their weapons at a military base in Kunduz, Afghanistan
October 22, 2003. A long-awaited U.N.-sponsored project to disarm,
demobilise and reintegrate 100,000 soldiers across Afghanistan was
under way in the north, a key step to bringing eventual peace to this
war-torn country. The "New Beginnings Programme," which lets soldiers
exchange their weapons for jobs, began in the northern province of
Kunduz this week. REUTERS/Richard Vogel/Pool
A Chinook helicopter hovers over U.S. troops in the village of Jegdelic, about 90 km (56 miles) southwest of Kabul, Afghanistan, in this picture taken on December 24, 2004. A U.S. military helicopter carrying up to 20 American troops crashed during an anti-guerrilla mission in eastern Afghanistan on Tuesday, U.S. officials said. The fate of those on board was not immediately known. Picture taken December 24, 2004. REUTERS/Ahmad Masood Am/mk BEST QUALITY AVAILABLE
An Afghan boy looks at U.S. soldiers as they patrol a village near the town of Makkor, southwest of Kabul April 20, 2007. REUTERS/Goran Tomasevic (AFGHANISTAN)
A U.S. soldier works with a shovel as a vehicle is stuck in mud, some 70km south of Ghazni, southeastern Afghanistan April 23, 2007. REUTERS/Goran Tomasevic (AFGHANISTAN)
British and a U.S. soldiers control the crowd during medical assistance in Kabul February 26, 2008. U.S. and British troops provided medical assistance worth of $50,000 to the Afghan locals in Kabul on Tuesday. REUTERS/Ahmad Masood (AFGHANISTAN)
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 (AFGHANISTAN)
U.S. Secretary of Defense Robert Gates (L) and U.S. Army General David McKiernan, the top U.S. and NATO Commander in Afghanistan (R) listen to Afghan governors and local officials during their visit to Forward Operating Base Airborne in the mountains of Wardak Province, Afghanistan, May 8, 2009. Gates on May 11, 2009 replaced the top U.S. and NATO commander in Afghanistan, U.S. Army General David McKiernan, less than a year after he took over the war effort there. Gates said he asked for McKiernan's resignation and recommended Army Lieutenant General Stanley McChrystal, a former commander of special operations forces, to take over command of 45,000 U.S. troops and about 32,000 other troops from non-U.S. NATO countries. REUTERS/Jason Reed (AFGHANISTAN MILITARY POLITICS)
U.S. soldiers of the 2-12 Infantry, 4th Brigade prepare to tow a broken-down improvised explosive device (IED) detecting Huskie vehicle during a patrol in the Pesh Valley in Afghanistan's Kunar Province July 30, 2009. REUTERS/Tim Wimborne (AFGHANISTAN CONFLICT)
U.S. soldiers kneel during a memorial ceremony for Captain Daniel Whitten and Private First Class Zachary Lovejoy from Charlie Company, 4th Brigade combat team,1-508, 82nd Parachute Infantry Regiment at the Remote Sweeney FOB in Zabul province, southern Afghanistan, February 8, 2010. CPT Whitten from Grimes, Iowa, and PFC Lovejoy from Albuquerque, New Mexico, were killed by an IED on February 2. when on patrol in southern Afghanistan.
REUTERS/Baz Ratner (AFGHANISTAN - Tags: CIVIL UNREST CONFLICT MILITARY)
Canadian soldiers play table football under flashlights at a military outpost near the village of Bazaar e Panjwaii, in the Panjwaii district of Kandahar province August 8, 2010. REUTERS/Bob Strong (AFGHANISTAN - Tags: CONFLICT MILITARY)
U.S. Army medic Staff Sergeant Rahkeem Francis with Charlie Company, 6-101 Combat Aviation Brigade, 101st Airborne Division, treats an Afghan boy with a broken leg onboard a medevac helicopter near the town of Marjah in Helmand Province, August 19, 2010. REUTERS/Bob Strong (AFGHANISTAN - Tags: CONFLICT MILITARY POLITICS)
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 (AFGHANISTAN - Tags: CONFLICT MILITARY IMAGES OF THE DAY POLITICS)
An Afghan shepherd walks with a flock of sheep past a U.S. Marines armored vehicle of the Weapons Company, 1st Battalion, 3rd Marines outside the Camp Gorgak in Helmand province, southern Afghanistan July 5, 2011. REUTERS/Shamil Zhumatov (AFGHANISTAN - Tags: POLITICS MILITARY ANIMALS IMAGES OF THE DAY)
First Sergeant Mac Miller from Comanche Troop 3rd Squadron 4th Cavalry lift weights as he exercises in Forward Operating Base Connolly in Nangarhar province, eastern Afghanistan, March 3, 2012. Picture taken March 3, 2012. REUTERS/Erik De Castro (AFGHANISTAN - Tags: MILITARY CONFLICT)
A U.S. Army soldier and a member of the Afghan Uniform Police arm wrestle prior to a joint patrol near Command Outpost AJK (short for Azim-Jan-Kariz, a near-by village) in Maiwand District, Kandahar Province, Afghanistan, January 28, 2013. REUTERS/Andrew Burton (AFGHANISTAN - Tags: POLITICS CIVIL UNREST MILITARY SOCIETY TPX IMAGES OF THE DAY)
A U.S. service member takes a "selfie" as U.S. President Barack Obama shakes hands with troops after delivering remarks at Bagram Air Base in Kabul, May 25, 2014. Obama, on a visit to Afghanistan, said on Sunday his administration would likely announce soon how many troops the United States will keep in the country, as it winds down its presence after nearly 13 years of war. REUTERS/Jonathan Ernst (AFGHANISTAN - Tags: POLITICS MILITARY)
Afghan children gesture at U.S. soldiers from Grim Company of the 3rd Cavalry Regiment as they stand guard near an Afghan police checkpoint during a mission near Forward Operating Base Fenty in the Nangarhar province of Afghanistan December 19, 2014. REUTERS/Lucas Jackson (AFGHANISTAN - Tags: CIVIL UNREST POLITICS MILITARY CONFLICT)
U.S. soldiers attend to a wounded soldier at the site of a blast in Kabul, Afghanistan June 30, 2015. At least 17 people were wounded in a suicide bomb attack on NATO troops as their truck convoy passed down the main road running between Kabul's airport and the U.S. embassy, police and health ministry officials said. REUTERS/Omar Sobhani TPX IMAGES OF THE DAY
A U.S. soldier keeps watch at the site of an explosion in Kabul, Afghanistan January 4, 2016. A large explosion struck close to Kabul airport on Monday, causing at least 10 casualties near to the area where a suicide bomber blew himself up earlier in the day in the latest in a series of attacks in the Afghan capital over the past week. REUTERS/Omar Sobhani