November 9, 2001 · Northern Afghanistan Theater

The first major city to fall in the 2001 campaign, Mazar-i-Sharif was taken by Northern Alliance commander Abdul Rashid Dostum — a former Soviet-backed warlord turned US partner — with a dozen US Special Forces soldiers on horseback calling in precision airstrikes. CIA officer Mike Spann became the first American killed in combat in Afghanistan during the subsequent Qala-i-Jangi prison uprising, where Taliban prisoners seized weapons and fought a brutal three-day battle inside the fort's mud walls.

November 13, 2001 · Northern Afghanistan Theater

Seven weeks after 9/11, the Taliban abandon Kabul without a major fight as Northern Alliance forces, backed by US Special Forces on horseback calling in B-52 strikes, sweep through northern Afghanistan. The capital falls in 24 hours. Afghans celebrate in the streets — women remove their burqas, men shave their beards, music plays publicly for the first time in five years. The speed of the Taliban collapse stuns the world.

November 25 – December 7, 2001 · Southern Afghanistan Theater

The Taliban heartland and birthplace of the movement, Kandahar was the final Taliban stronghold. Hamid Karzai — the future Afghan president — had parachuted into southern Afghanistan weeks earlier with a satellite phone and 30 fighters, rallying Pashtun tribes against the Taliban. US Special Forces and CIA officers backed Karzai while Marines established the first US forward operating base at Camp Rhino south of the city. After two weeks of fighting, Mullah Omar and the Taliban leadership fled on motorcycles into the Pakistani tribal areas. Kandahar fell on December 7.

December 6–17, 2001 · Eastern Afghanistan Theater

US forces, Afghan militias, and Special Operations troops close in on Tora Bora — a mountain cave complex in the White Mountains near the Pakistani border where Osama bin Laden and hundreds of Al-Qaeda fighters are hiding. CIA officers on the ground beg for US Army Rangers to block escape routes into Pakistan. The request is denied — senior commanders do not want to 'Americanize' the fight. Bin Laden and most of his fighters escape across the Pakistani border.

March 2–18, 2002 · Shahi-Kot Valley Theater

Operation Anaconda attempts to encircle and destroy several hundred Al-Qaeda and Taliban fighters in the Shahi-Kot Valley in a hammer-and-anvil operation. The plan goes wrong almost immediately — Afghan troops meant to be the blocking force don't materialize, intelligence underestimates enemy numbers, and enemy fighters are far more capable than expected. Eight Americans are killed including in the famous SEAL Team Six Takur Ghar battle where Petty Officer Neil Roberts falls from a helicopter.

July 13, 2008 · Kunar Province Theater

In the early morning hours of July 13, a force estimated at 200 Taliban fighters launches a coordinated assault on Combat Outpost Kahler near the village of Wanat in Kunar Province. Nine American soldiers are killed — the deadliest single engagement for US forces in Afghanistan in three years. The platoon of paratroopers from the 173rd Airborne Brigade, having just established the outpost, fought off the assault with .50-caliber machine guns and close air support before relief forces arrived.

October 3, 2009 · Nuristan Province Theater

A force of roughly 300 Taliban fighters attacks Combat Outpost Keating — located in a valley at the bottom of three steep ridgelines in Nuristan Province, a position that experienced officers had described as militarily indefensible. Eight American soldiers are killed and 22 wounded before air support, including A-10 Warthogs and B-1 bombers, breaks the assault. Staff Sgt. Clint Romesha and Spec. Ty Carter both receive the Medal of Honor for their actions that day. The outpost is abandoned and destroyed two days later.

February 13 – June 2010 · Helmand Province Theater

The largest Marine operation since the Battle of Fallujah, Operation Moshtarak sends 15,000 US, NATO, and Afghan troops into Marjah — a Taliban stronghold and major opium-producing district in Helmand Province. The operation is fought transparently, with the US announcing the assault in advance to minimize civilian casualties. Marines take the town but find the promised Afghan government 'in a box' — a functioning administration ready to move in — is illusory.

June 2010 – September 2011 · Helmand Province Theater

Sangin, a district center in northern Helmand Province, was handed from British to US Marine control in 2010 after the British — who had lost more casualties per-capita there than anywhere else in their deployment — could no longer sustain it. Marines from 3/5 'Darkhorse' suffered catastrophic losses in the IED-saturated poppy fields and mud-walled compounds, losing 25 killed in five months. The district sat astride the Taliban's primary opium-trafficking route and was defended fiercely for economic as much as ideological reasons.

September 28 – October 13, 2015 · Northern Afghanistan Theater

The Taliban capture Kunduz — Afghanistan's fifth-largest city and the capital of Kunduz Province — for the first time since 2001, sending shockwaves through the country. Afghan security forces, riddled with corruption and leadership problems, collapse in the face of a coordinated Taliban assault. US Special Forces and air support assist the Afghan counterattack. In the chaos, a US AC-130 gunship repeatedly strikes the Médecins Sans Frontières (Doctors Without Borders) hospital in Kunduz, killing 42 people including patients and staff, in one of the most controversial incidents of the war.

August 15, 2021 · Afghanistan Theater

In the span of eleven days in August 2021, the Taliban capture every provincial capital in Afghanistan and enter Kabul as the US-backed government dissolves. President Ghani flees by helicopter. Thousands of Afghans flood Kabul's airport, clinging to the outside of US military aircraft. The collapse is complete — the government the US spent 20 years and $2 trillion building evaporates in less time than it took to plan a single battle.