After the Taliban government refused to hand over terrorist leader Osama bin Laden in the wake of al-Qaeda’s September 11, 2001, attacks, the United States invaded Afghanistan. The Taliban leadership quickly lost control of the country and relocated to southern Afghanistan and across the border to Pakistan. From there, they waged an insurgency against the Western-backed government in Kabul, Afghan national security forces, and international coalition troops.
When the U.S.-led coalition formally ended its combat mission in 2014, the ANDSF was put in charge of Afghanistan’s security. The ANDSF, however, faced significant challenges in holding territory and defending population centers, while the Taliban continued to attack rural districts and carry out suicide attacks in major cities. The war remained largely a stalemate for nearly six years, despite a small U.S. troop increase in 2017, continuing combat missions, and a shift in U.S. military strategy to target Taliban revenue sources, which involved air strikes against drug labs and opium production sites.
The Taliban continued to contest territory, including provincial capitals, across the country. The group briefly seized the capital of Farah Province in May 2018, and in August 2018 it captured the capital of Ghazni Province, holding the city for nearly a week before U.S. and Afghan troops regained control. The ANDSF suffered heavy casualties in recent years.
In February 2020, after more than a year of direct negotiations, the U.S. government and the Taliban signed a peace agreement that set a timeline for the withdrawal of U.S. troops from Afghanistan. Under the agreement, the United States pledged to draw down U.S. troops to approximately 8,500 within 135 days and complete a full withdrawal within fourteen months. In return, the Taliban pledged to prevent territory under its control from being used by terrorist groups and enter into negotiations with the Afghan government. However, no official cease-fire was put into place. After a brief reduction in violence, the Taliban quickly resumed attacks on Afghan security forces and civilians. Direct talks between the Afghan government and the Taliban began months after the agreed upon start of March 2020, faced multiple delays, and ultimately made little progress. Violence across Afghanistan continued in 2020 and 2021 as the United States increased air strikes and raids targeting the Taliban. Meanwhile, the Taliban attacked Afghan government and Afghan security forces targets and made territorial gains.
Civilian casualties across Afghanistan have remained high over the past several years. The United Nations documented a then–record high of 10,993 civilian casualties in 2018. Although 2019 saw a slight decline, civilian casualties exceeded 10,000 for the sixth year in a row and brought the total UN-documented civilian casualties since 2009 to more than 100,000. Despite another decline in 2020, the first half of 2021 saw a record high number of civilian casualties as the Taliban ramped up their military offensive amid the withdrawal of international troops.
In addition to the Taliban’s offensive, Afghanistan faces a threat from the Islamic State in Khorasan, which has also expanded its presence in several eastern provinces, attacked Kabul, and targeted civilians with suicide attacks.
Uncertainty surrounding the future of international assistance has strained the Afghan economy. Although the United States and its allies pledged in late 2020 to continue providing support to the Afghan government, they could reduce aid following the Taliban takeover. Such a move could compound Afghanistan’s deteriorating economic situation.
The United States has an interest in attempting to preserve the many political, human rights, and security gains that have been achieved in Afghanistan since 2001. The Taliban takeover of the country could once again turn Afghanistan into a terrorist safe haven, as the group is believed to maintain ties with al-Qaeda. The takeover also threatens to reverse advances made in securing the rights of women and girls. Moreover, increasing internal instability, a mass exodus of refugees, and a growing humanitarian crisis could have regional ramifications as neighboring countries respond. In addition, Pakistan, India, Iran, and Russia are all likely to compete for influence in Kabul and with subnational actors.
In April 2021, President Joe Biden announced that U.S. military forces would leave Afghanistan by September 2021. The Taliban, which had continued to capture and contest territory across the country despite ongoing peace talks with the Afghan government, ramped up attacks on Afghan National Defense and Security Forces (ANDSF) bases and outposts and began to rapidly seize more territory. In May 2021, the U.S. military accelerated the pace of its troop withdrawal. By the end of July 2021, the United States had completed nearly 95 percent of its withdrawal, leaving just 650 troops to protect the U.S. embassy in Kabul.
In the summer of 2021, the Taliban continued its offensive, threatening government-controlled urban areas and seizing several border crossings. In early August, the Taliban began direct assaults on multiple urban areas, including Kandahar in the south and Herat in the west. On August 6, 2021, the Taliban captured the capital of southern Nimruz Province, the first provincial capital to fall. After that, provincial capitals began to fall in rapid succession. Within days, the Taliban captured more than ten other capitals, including Mazar-i-Sharif in the north and Jalalabad in the east, leaving Kabul the only major urban area under government control. On August 15, 2021, Taliban fighters entered the capital, leading Afghan President Ashraf Ghani to flee the country and the Afghan government to collapse. Later that day, the Taliban announced they had entered the presidential palace, taken control of the city, and were establishing checkpoints to maintain security.
The speed of the Taliban’s territorial gains and collapse of both the ANDSF and Afghan government surprised U.S. officials and allies—as well as, reportedly, the Taliban itself—despite earlier intelligence assessments of the situation on the ground. The Biden administration authorized the deployment of an additional six thousand troops to assist with the evacuation of U.S. and allied personnel, as well as thousands of Afghans who worked with the United States and were attempting to flee. The speed of the Afghan government’s collapse threatens a mass exodus of refugees from Afghanistan and has exacerbated an already dire humanitarian crisis.