Al-Qaeda in the context of Timber Sycamore

The war in Afghanistan was a prolonged armed conflict lasting from 2001 to 2021. It began with an invasion by a United States–led coalition under the name Operation Enduring Freedom in response to the September 11 attacks carried out by the Taliban-allied and Afghanistan-based al-Qaeda. The Taliban were expelled from major population centers by American-led forces supporting the anti-Taliban Northern Alliance, thus toppling the Taliban-ruled Islamic Emirate. Three years later, the American-sponsored Islamic Republic was established, but by then the Taliban, led by founder Mullah Omar, had reorganized and begun an insurgency against the Afghan government and coalition forces. The conflict ended almost twenty years later as the 2021 Taliban offensive reestablished the Islamic Emirate. It was the longest war in United States military history, surpassing the Vietnam War by six months.

Following the September 11 attacks, masterminded by al-Qaeda leader Osama bin Laden, American president George W. Bush demanded that the Taliban immediately extradite him to the United States and close down al-Qaeda's camps in Afghanistan; the Taliban refused and demanded evidence of bin Laden's guilt before offering to hand him over to a neutral country. The U.S. dismissed these offers and proceeded with the invasion. After expelling the Taliban and their allies, the American-led coalition remained in Afghanistan, forming the International Security Assistance Force (ISAF)—sanctioned by the United Nations—with the goal of creating a new democratic authority in the country that would prevent the Taliban from returning to power. A new Afghan Interim Administration was established, and international rebuilding efforts were launched. By 2003, the Taliban had reorganized and launched a widespread insurgency against the new Afghan government and coalition forces. Insurgents from the Taliban and other Islamist groups waged asymmetric warfare, fighting with guerrilla warfare in the countryside, suicide attacks

The World Trade Center, in Lower Manhattan, New York City, was destroyed after a series of terrorist attacks on September 11, 2001, killing almost 3,000 people at the site. Two commercial airliners hijacked by al-Qaeda members were deliberately flown into the complex's Twin Towers, at the time among the five tallest buildings in the world. The plane impacts dealt significant structural damage to the skyscrapers and started large fires in the towers, eventually resulting in both undergoing a total progressive collapse.

The North Tower (WTC 1) was the first building to be hit when American Airlines Flight 11 crashed into it at 8:46 a.m., causing it to collapse at 10:28 a.m. after burning for one hour and 42 minutes. At 9:03 a.m., the South Tower (WTC 2) was struck by United Airlines Flight 175; it collapsed at 9:59 a.m. after burning for 56 minutes.

The September 11 attacks, colloquially known as 9/11, were four coordinated Islamist terrorist suicide attacks by al-Qaeda against the United States in 2001. Nineteen terrorists hijacked four commercial airliners, then flew one into each of the Twin Towers at the World Trade Center in New York City, and another into the Pentagon, the headquarters of the U.S. Department of Defense, in Arlington County, Virginia. The fourth plane crashed in a rural Pennsylvania field during a passenger revolt. In response to the attacks, the United States waged the global war on terror over decades, to eliminate hostile groups deemed terrorist organizations, and the governments purported to support them.

Ringleader Mohamed Atta flew American Airlines Flight 11 into the North Tower of the World Trade Center complex at 8:46 a.m. Seventeen minutes later at 9:03 a.m., United Airlines Flight 175 hit the South Tower. Both collapsed within an hour and forty-two minutes, destroying the remaining five structures in the complex. American Airlines Flight 77 crashed into the Pentagon at 9:37 a.m., causing a partial collapse. The fourth and final flight, United Airlines Flight 93, was believed by investigators to target either the United States Capitol or the White House. Alerted to the previous attacks, the passengers revolted against the hijackers who crashed the aircraft into a field near Shanksville, Pennsylvania, at 10:03 a.m. The Federal Aviation Administration ordered an indefinite ground stop for all air traffic in U.S. airspace, preventing any further aircraft departures until September 13 and requiring all airborne aircraft to return to their point of origin or divert to Canada. The actions undertaken in Canada to support incoming aircraft and their occupants were collectively titled Operation Yellow Ribbon.

Terrorism, in its broadest sense, is the use of violence against non-combatants to achieve political or ideological aims. The term is used in this regard primarily to refer to intentional violence during peacetime or in the context of war against non-combatants. There are various different definitions of terrorism, with no universal agreement about it. Different definitions of terrorism emphasize its randomness, its aim to instill fear, and its broader impact beyond its immediate victims.

Modern terrorism, evolving from earlier iterations, employs various tactics to pursue political goals, often leveraging fear as a strategic tool to influence decision makers. By targeting densely populated public areas such as transportation hubs, airports, shopping centers, tourist attractions, and nightlife venues, terrorists aim to instill widespread insecurity, prompting policy changes through psychological manipulation and undermining confidence in security measures.

The war on terror, officially the Global War on Terrorism (GWOT), is a global military campaign initiated by the United States in response to the September 11 attacks in 2001. A global conflict spanning multiple wars, some researchers and political scientists have argued that it replaced the Cold War.

The main targets of the campaign were militant Islamist movements such as al-Qaeda, the Taliban and their allies. Other major targets included the Ba'athist regime in Iraq, which was deposed in an invasion in 2003, and various militant factions that fought during the ensuing insurgency. Following its territorial expansion in 2014, the Islamic State also emerged as a key adversary of the United States.

The Special Collection Service (SCS), codenamed F6, is a highly classified joint U.S. Central Intelligence Agency–National Security Agency program charged with inserting eavesdropping equipment in difficult-to-reach places, such as foreign embassies, communications centers, and foreign government installations. Established in the late 1970s and headquartered in Beltsville, Maryland, the SCS has been involved in operations ranging from the Cold War to hunting Al-Qaeda after the September 11 attacks.

Ahmed Hussein al-Sharaa (born 29 October 1982), also known by his nom de guerre Abu Mohammad al-Julani, is a Syrian politician, revolutionary, and former rebel commander who has served as the president of Syria since 2025. He previously served as the emir of Hay'at Tahrir al-Sham (HTS) from 2017 to 2025 and was Syria's de facto leader from December 2024 until his appointment as president.

Born in Riyadh, Saudi Arabia, to a Syrian Sunni Muslim family from Daraa and the Golan Heights, he grew up in Syria's capital, Damascus. Al-Sharaa joined al-Qaeda in Iraq shortly before the 2003 invasion of Iraq and fought for three years in the Iraqi insurgency. American forces captured and imprisoned him from 2006 to 2011. His release coincided with the Syrian Revolution against the Ba'athist dictatorship of Bashar al-Assad. Al-Sharaa created the al-Nusra Front in 2012 with the support of al-Qaeda to topple the Assad regime in the Syrian civil war. As emir of the al-Nusra Front, al-Sharaa built a stronghold in the northwestern Idlib Governorate. He resisted Abu Bakr al-Baghdadi's attempts to merge al-Nusra Front with the Islamic State, leading to armed conflict between the two groups. In 2016, al-Sharaa cut al-Nusra's ties with al-Qaeda and launched a crackdown on its loyalists. Since breaking with al-Qaeda, he has sought international legitimacy by presenting a more moderate view of himself, renouncing transnational jihadism against Western nations, and focusing on governance in Syria while vowing to protect Syria's minorities.

Jemaah Islamiyah (Arabic: الجماعة الإسلامية, al-Jamāʿah al-Islāmiyyah, meaning "Islamic Congregation", frequently abbreviated JI) was a Southeast Asian Islamist militant group based in Indonesia, which was dedicated to the establishment of an Islamic state in Southeast Asia. On 25 October 2002, immediately following the JI-perpetrated 2002 Bali bombings, JI was added to the UN Security Council Resolution 1267.

JI was a transnational organization with cells in Indonesia, Singapore, Malaysia and the Philippines. In addition to Al-Qaeda, the group is also alleged to have links to the Moro Islamic Liberation Front and Jamaah Ansharut Tauhid, a splinter cell of the JI which was formed by Abu Bakar Baasyir on 27 July 2008. The group has been designated as a terrorist group by the United Nations, Australia, Canada, China, Japan, the United Kingdom and the United States. It remained very active in Indonesia where it publicly maintained a website as of January 2013.

On 30 September 2015, Russia launched a military intervention in Syria after a request by the regime of Bashar al-Assad for military support in its fight against the Syrian opposition and Islamic State (IS) in the Syrian civil war. The intervention began with extensive air strikes across Syria, focused on strongholds of opposition factions such as the Free Syrian Army, the Revolutionary Command Council, and Sunni militant groups comprising the Army of Conquest coalition. In line with the Assad regime's rhetoric, Syrian military chief Ali Abdullah Ayoub depicted Russian airstrikes as part of a general campaign against "terrorism." Russian special operations forces, military advisors and private military contractors like the Wagner Group were also sent to Syria to support the Assad regime, which was on the verge of collapse. Prior to the intervention, Russian involvement had included diplomatic support for Assad and billions of dollars' worth of arms and equipment for the Syrian Armed Forces. In December 2017, the Russian government announced that its troops would be deployed to Syria permanently.

At the onset of the intervention, the Syrian government controlled only 26% of Syrian territory. Although Russia initially portrayed its intervention as a "war against terrorism" solely targeting the Islamic State, Russia employed scorched-earth methods against civilian areas and Syrian opposition strongholds opposed to IS and Al-Qaeda. Weeks after the intervention began, Russian officials disclosed that President Vladimir Putin's chief objectives were maintaining the allied Ba'athist government in Damascus and capturing territories from American-backed Free Syrian militias, with a broader geo-political objective of rolling back U.S. influence. In a televised interview in October 2015, Putin said that the military operation had been thoroughly prepared in advance. He defined Russia's goal in Syria as "stabilising the legitimate power in Syria and creating the conditions for political compromise". In 2016 alone, more than 80% of Russian aerial attacks targeted opposition militias fighting the Islamic State. Despite Russia's extensive bombing of opposition strongholds, the territory under the Assad regime's actual control shrank from 26% of Syria in 2015 to 17% in early 2017.

The Taliban, which also refers to itself by its state name, the Islamic Emirate of Afghanistan, is an Afghan political and militant organization with an ideology comprising elements of the Deobandi movement of Islamic fundamentalism and Pashtun nationalism. It ruled approximately 90% of Afghanistan from 1996 to 2001, before it was overthrown by an American-led invasion after the September 11 attacks carried out by the Taliban's ally al-Qaeda. Following a 20-year insurgency and the departure of coalition forces, the Taliban recaptured Kabul in August 2021, overthrowing the Islamic Republic, and now controls all of Afghanistan. The Taliban has been condemned for restricting human rights, including women's rights to work and have an education, and for the persecution of ethnic minorities. It is designated as a terrorist organization by several countries, and the Taliban government is largely unrecognized by the international community.

The Taliban emerged in 1994 as a prominent faction in the Second Afghan Civil War (1992–1996) and largely consisted of warlords from the Pashtun areas of eastern and southern Afghanistan. Under the leadership of Mullah Omar, the movement spread through most of Afghanistan, shifting power away from the Islamic State of Afghanistan, as well as other Mujahideen militants. The Taliban seized Kabul in 1996 and established the First Islamic Emirate of Afghanistan that was opposed by the Northern Alliance, which maintained international recognition as a continuation of the Islamic State.

Shortly after the September 11 attacks in 2001, the United States declared the war on terror and subsequently led a multinational military operation against Taliban-ruled Afghanistan. The stated goal was to dismantle al-Qaeda, which had executed the attacks under the leadership of Osama bin Laden, and to deny Islamist militants a safe base of operations in Afghanistan by toppling the ruling Taliban government. The United Kingdom was a key ally of the United States, offering support for military action from the start of the invasion preparations. The American military presence in Afghanistan greatly bolstered the Northern Alliance, which had been locked in a losing fight with the Taliban during the Afghan Civil War. Prior to the beginning of the United States' war effort, the Taliban had seized around 85% of Afghanistan's territory as well as the capital city of Kabul, effectively confining the Northern Alliance to Badakhshan Province and smaller surrounding areas. The American-led invasion on 7 October 2001, marked the first phase of what would become the 20-year-long War in Afghanistan.

After the September 11 attacks, American president George W. Bush demanded that the Taliban government extradite Osama bin Laden to the United States and also expel al-Qaeda militants from Afghanistan; bin Laden had been active in Afghanistan since the Soviet–Afghan War and was already wanted by the Federal Bureau of Investigation for his role in the 1998 United States embassy bombings. The Taliban declined to extradite bin Laden and further ignored demands to shut down terrorist bases or extradite other suspected terrorists. In response, the United States launched Operation Enduring Freedom on 7 October 2001, alongside the United Kingdom. The two countries were later joined by a large multinational force, including Afghanistan's local Northern Alliance. The invasion effort made rapid progress for the next two months as the coalition captured Kabul on 13 November and toppled the Taliban by 17 December, after which international military bases were set up near major cities across the country. However, most members of al-Qaeda and the Taliban were not captured: during the Battle of Tora Bora, several fighters including bin Laden, the founder of al-Qaeda escaped into neighboring Pakistan or otherwise retreated to remote regions deep within the Hindu Kush.

Following the September 11 attacks in 2001, several countries began military operations against Al-Qaeda and the Taliban during Operation Enduring Freedom (OEF) in Afghanistan. After the initial bombing operations, Operation Crescent Wind, OEF was the initial combat operations, and during 2002 and 2003.

This list covers United States and other states' forces and other forms of support for OEF from October 2001. Some nations' operations in Afghanistan continued as part of NATO's International Security Assistance Force (ISAF). For example, United States troops were deployed both in the OEF and ISAF.

Operation Enduring Freedom (OEF) was the official name used by the U.S. government for both the first stage (2001–2014) of the war in Afghanistan (2001–2021) and related military operations during broader-scale global war on terrorism. On 7 October 2001, in response to the September 11 attacks, President George W. Bush announced that airstrikes against al-Qaeda and the Taliban had begun in Afghanistan. Beyond the military actions in Afghanistan, U.S military command structures operating under the Operation Enduring Freedom banner were also affiliated with several counterterrorism missions in other countries, such as OEF-Philippines and OEF-Trans Sahara.

After 13 years, on 28 December 2014, President Barack Obama announced the end of Operation Enduring Freedom in Afghanistan. Subsequent operations in Afghanistan by the United States' military forces, both non-combat and combat, occurred under the name Operation Freedom's Sentinel.

Muhammad Umar Mujahid (1959 – 23 April 2013), commonly known as Mullah Omar or Muhammad Omar, was an Afghan militant leader who served as the first supreme leader of Afghanistan from 1996 to 2001. He founded the Taliban in 1994 and served as its first supreme leader until his death in 2013. During the Third Afghan Civil War, the Taliban fought the Northern Alliance and took control of most of the country, establishing its First Islamic Emirate. Shortly after al-Qaeda carried out the September 11 attacks, the Taliban government was toppled by an American invasion of Afghanistan, prompting Omar to go into hiding; he successfully evaded capture by the American-led coalition before dying in 2013 from tuberculosis.

Born into a religious family in Kandahar, Omar was educated at local madrasas in Afghanistan. After Afghanistan was invaded by the Soviet Union in 1979, he joined the Afghan mujahideen to fight in the Soviet–Afghan War and he was trained by Amir Sultan Tarar. He served as an important rebel commander during several skirmishes, losing his right eye in an explosion. The Soviets eventually withdrew from the country in 1989 and Afghanistan's Soviet-backed Democratic Republic was toppled in 1992, triggering the Second Afghan Civil War. While initially remaining quiet and focused on continuing his studies, Omar became increasingly discontent with what he perceived as fasād in the country, ultimately prompting him to return to fighting in the Civil War.

Osama bin Mohammed bin Awad bin Laden (10 March 1957 – 2 May 2011) was the founder and first general emir of al-Qaeda. Ideologically a pan-Islamist, Bin Laden participated in the Afghan mujahideen during the Soviet–Afghan War of the 1980s, and supported the Bosnian mujahideen during the Bosnian War of the 1990s. Opposed to American foreign policy in the Middle East, Bin Laden declared war on the United States in 1996 and supervised numerous terrorist attacks in various countries, including the September 11 attacks in 2001 in the U.S.

Born in Riyadh to the aristocratic bin Laden family, he studied at Saudi and foreign universities until 1979, when he joined the mujahideen fighting against the Soviet invasion of Afghanistan. In 1984, he co-founded Maktab al-Khidamat, which recruited foreign mujahideen into the war. As the Soviet war in Afghanistan came to an end, Bin Laden founded al-Qaeda in 1988 to carry out worldwide jihad. In the Gulf War, Bin Laden's offer of support to Saudi Arabia against Iraq was rejected by the Saudi royal family, which instead sought American aid.

Istihlal (Arabic: استحلال istiḥlāl) is a term used in Islamic jurisprudence, or fiqh, to refer to the act of regarding some action as permissible, or halaal, although it is haraam; the implication is that such a regard is an erroneous and improper distortion of Islamic law. The word "istihlal" is derived as Stem X of the Arabic consonantal root ح-ل-ل meaning "to untie", "to solve", "to dissolve", "to open", "to release", etc.

The term "istihlal" came to prominence in the Western news media on 11 March 2005, the first anniversary of the Madrid bombing attacks of 2004, when the Islamic Commission of Spain (La Comisión Islámica de España) issued a fatwa, or religious opinion, denouncing Osama bin Laden and al-Qaeda for engaging in istihlal with respect to the waging of jihad through terrorism, and the killing of women, children, and noncombatants.

The September 11 attacks, colloquially and perhaps more commonly known as 9/11, were four coordinated Islamist terrorist suicide attacks by al-Qaeda against the United States in 2001. Nineteen terrorists hijacked four commercial airliners, then flew one into each of the Twin Towers at the World Trade Center in New York City, and another into the Pentagon, the headquarters of the U.S. Department of Defense, in Arlington County, Virginia. The fourth plane crashed in a rural Pennsylvania field during a passenger revolt. In response to the attacks, the United States launched and waged the global war on terror over two decades, with the mission to eliminate hostile groups deemed terrorist organizations, and the governments purported to support them.

Ringleader and hijacker Mohamed Atta flew American Airlines Flight 11 into the North Tower of the World Trade Center complex at 8:46 a.m. Seventeen minutes later at 9:03 a.m., hijacker Marwan al-Shehhi flew United Airlines Flight 175 into the South Tower. Both collapsed within an hour and forty-two minutes, destroying the remaining five structures in the complex. Hijacker Hani Hanjour flew American Airlines Flight 77 into the Pentagon at 9:37 a.m., causing a partial collapse. The fourth and final flight, United Airlines Flight 93, flown by hijacker Ziad Jarrah, was believed by investigators to target either the United States Capitol or the White House. Alerted to the previous attacks, the passengers revolted against the hijackers who crashed the aircraft into a field near Shanksville, Pennsylvania, at 10:03 a.m. The Federal Aviation Administration ordered an indefinite ground stop for all air traffic in U.S. airspace, preventing any further aircraft departures until September 13 and requiring all airborne aircraft to return to their point of origin or divert to Canada. The actions undertaken in Canada to support incoming aircraft and their occupants were collectively titled Operation Yellow Ribbon.

The New York Marriott World Trade Center, also known as 3 World Trade Center (3 WTC), was a 22-story, 825-room hotel in New York City, within the original World Trade Center complex in downtown Manhattan. It opened in April 1981 as the Vista International Hotel, the first major hotel since 1836 to open in Manhattan south of Canal Street.

The hotel was damaged in the World Trade Center bombing by al-Qaeda terrorists on February 26, 1993. The Port Authority of New York and New Jersey considered demolishing the building, but instead decided to repair it. The building's structure was reinforced, and it re-opened in November 1994. In November 1995, it was bought by Marriott Corporation and renamed the New York Marriott World Trade Center.