A timeline of key events in Afghanistan's 40 years of wars

The former Soviet Union marched into Afghanistan on Christmas Eve, 1979, claiming it was invited by the new Afghan communist leader, Babrak Karmal, setting the country on a path of 40 years of seemingly endless wars and conflict.

Here is a timeline of some key dates in Afghanistan's 40 years of wars:

December 25, 1979  Soviet Red Army crosses the Oxus River into Afghanistan. In neighboring Pakistan, Afghan mujahedeen, or Islamic holy warriors, are assembling, armed and financed by the U.S. for an anti-communist war.

1980s  CIA's covert Operation Cyclone funnels weapons and money for the war through Pakistani dictator Mohammed Zia-ul Haq.

1983  President Ronald Reagan meets with mujahedeen leaders, calling them freedom fighters, at the White House.

September 1986  The US provides the mujahedeen with shoulder-held anti-aircraft Stinger missiles, which turned around the course of the war and sped-up negotiated Soviet withdrawal.

January 1987  Afghan Communist President Najibullah launches National Reconciliation Program to encourage the mujahedeen to join a new government of national reconciliation; they refuse.

February 15, 1989- The last Soviet soldier leaves Afghanistan, ending 10 years of occupation April 1992  Mujahedeen groups enter Kabul as Najibullah tries to flee. He is stopped at the airport and put under house arrest at a U.N. compound.

1992-1996  A power-sharing deal among seven mujahedeen leaders falls apart.

1994  The Taliban emerge in southern Kandahar, mainly from the ranks of former mujahedeen fighters.

September 26, 1996  The Taliban take Kabul after sweeping across the country with hardly a fight.

1996-2001 Though initially welcomed as an end to the fighting, the Taliban rule with a heavy hand under Mullah Mohammed Omar, imposing strict Islamic edicts, denying women the right to work and girls the right to go to school.

2000  The Taliban eradicate opium production but laborers who lived off the poppy fields become even poorer.

March 2001  The Taliban dynamite the world's largest standing Buddha statues in Bamyan province, to global shock.

September 9, 2001  Two Arab-speaking suicide bombers, posing as journalists with Belgium passports, kill Masood in northern Takhar province. 

September 2001  Washington gives Mullah Omar an ultimatum: hand over bin Laden and dismantle militant training camps or prepare to be attacked. 

October 7, 2001  A US-led coalition launches an invasion of Afghanistan.

November 13, 2001  The Taliban flee Kabul for Kandahar as the US-led coalition marches into the Afghan capital with the Northern Alliance.

December 5, 2001 - The Bonn Agreement is signed in Bonn, Germany, giving the majority of power to the Northern Alliance's key players and strengthening the warlords who had ruled between 1992 and 1996.

December 7, 2001  Mullah Omar leaves Kandahar and the Taliban regime officially collapses.

December 13, 2001  Karzai arrives in Kabul; contrary to the Bonn Agreement, militias loyal to warlords also enter the Afghan capital.

December 22, 2001  Karzai is sworn in as chairman of a 29-member governing council established under the Bonn Agreement.

2004 and 2009  General elections are held and Karzai is elected president for two consecutive terms, the limit under the Afghan constitution.

April 5, 2014  Deeply flawed election results in the two front-runners, Ashraf Ghani and Abdullah Abdullah, both claiming victory. U.S. Secretary of State John Kerry negotiates a power-sharing deal for a so-called Unity Government, with Ghani serving as president and Abdullah as chief executive.

December 8, 2014  American and NATO troops formally end their combat mission, transitioning to a support and training role though President Barack Obama had authorized U.S. forces to carry out operations against Taliban and al-Qaida targets.

2015-2018  The Taliban surge further, staging near-daily attacks targeting Afghan and U.S. forces; scores of civilians die in the crossfire. An Islamic State group affiliate emerges in the east; the Taliban seize control of nearly half the country.

September 2018  Seeking to fulfill his election promise to bring U.S. troops home, President Donald Trump appoints veteran Afghan-American diplomat Zalmay Khalilzad as negotiator with the Taliban.

2018-2019  Zalmay engages in on-again, off-again talks with the Taliban, mainly in the Gulf Arab state of Qatar where the insurgents maintain a political office. The Taliban refuse to negotiate with the Kabul government September 9, 2019  After a particularly intense escalation in Taliban attacks, including a Kabul bombing that killed a U.S. soldier, Trump scraps talks with the Taliban.

September 28, 2019  Presidential elections are held but official results are not known for months.

November 24, 2019  Trump visits U.S. troops in Afghanistan on Thanksgiving, says the Taliban want to make a deal and signals the Qatar negotiations are back on.

February 15, 2020  Washington says a temporary reduction in violence has been agreed upon with the Taliban as first step toward a final peace deal.

February 18, 2020  Afghanistan's election commission declares Ghani the official winner of September elections; his rival Abdullah refuses to recognize the results and instead declares himself the winner.

February 29, 2020  The U.S. and the Taliban sign a deal in Doha, Qatar, laying out the withdrawal of U.S. troops from Afghanistan; the deal also envisions intra-Afghan talks on a future political road map.