War on terror

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, and is one of the most recent global conflicts 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 term "war on terror" uses war as a metaphor to describe a variety of actions which fall outside the traditional definition of war. U.S. president George W. Bush first used the term "war on terrorism" on 16 September 2001, and then "war on terror" a few days later in a formal speech to Congress. Bush indicated the enemy of the war on terror as "a radical network of terrorists and every government that supports them". The initial conflict was aimed at al-Qaeda, with the main theater in Afghanistan and Pakistan, a region that would later be referred to as "AfPak". The term "war on terror" was immediately criticized by individuals including Richard Myers, then chairman of the Joint Chiefs of Staff, and eventually more nuanced terms came to be used by the Bush administration to define the campaign. While "war on terror" was never used as a formal designation of U.S. operations, a Global War on Terrorism Service Medal was and is issued by the U.S. Armed Forces.

During the 2020s, the war on terror has decreased in volume and intensity following the closure of the wars in Iraq (2011, with residual operations until 2021) and Afghanistan (complete withdrawal in 2021). This shift represents a transition from large-scale military interventions—with hundreds of thousands of troops, ground invasions, and prolonged occupations—to a more surgical, hybrid, and sustainable approach centered on intelligence, selective strikes, and regional alliances. For their part, the U.S. and NATO prioritize cyber defense, online counter-narratives, and cooperation with allies, which reduces media "noise" and their own casualties. On July 31, 2022, Ayman al-Zawahiri, Osama bin Laden's key successor, was killed in a US drone strike in Kabul, Afghanistan, marking the end of decades of centralized leadership in al-Qaeda. As of 2025, various global operations in the campaign are ongoing, including a U.S. military intervention in Somalia. Meanwhile, in 2025, airstrikes continue in Yemen. According to the Costs of War Project, the post-9/11 wars of the campaign have displaced 38 million people, the second largest number of forced displacements of any conflict since 1900, and caused more than 4.5 million deaths (direct and indirect) in Afghanistan, Iraq, Libya, Pakistan, Somalia, Syria and Yemen. They also estimate that it has cost the U.S. Treasury over $8 trillion.

While support for the "war on terror" was high among the American public during its initial years, it had become deeply unpopular by the late 2000s. Controversy over the war has focused on its morality, casualties, and continuity, with critics questioning government measures that infringed civil liberties and human rights. Critics have notably described the Patriot Act as "Orwellian" due to its substantial expansion of the federal government's surveillance powers. Controversial practices of coalition forces have been condemned, including drone warfare, surveillance, torture, extraordinary rendition and various war crimes. The participating governments have been criticized for implementing authoritarian measures, repressing minorities, fomenting Islamophobia globally, and causing negative impacts to health and environment. Security analysts assert that there is no military solution to the conflict, pointing out that terrorism is not an identifiable enemy, and have emphasized the importance of negotiations and political solutions to resolve the underlying roots of the crises.

The phrase war on terror was used to refer specifically to the military campaign led by the United States, the United Kingdom, and allied countries against organizations and regimes identified by them as terrorist, and usually excludes other independent counter-terrorist operations and campaigns such as those by Russia and India. The conflict has also been referred to by other names, such as "World War IV", "World War III", "Bush's War on Terror", "The Long War", "The Forever War", "The Global War on Terror", "The War Against al-Qaeda", or "The War of Terror".

The phrase "war against terrorism" existed in North American popular culture and U.S. political parlance prior to the war on terror. But it was not until the 11 September attacks that it emerged as a globally recognizable phrase and part of everyday lexicon. Tom Brokaw, having just witnessed the collapse of one of the towers of the World Trade Center, declared "Terrorists have declared war on [America]." On 16 September 2001, at Camp David, U.S. president George W. Bush used the phrase war on terrorism in an ostensibly unscripted comment when answering a journalist's question about the impact of enhanced law enforcement authority given to the U.S. surveillance agencies on Americans' civil liberties:

"This is a new kind of—a new kind of evil. And we understand. And the American people are beginning to understand. This crusade, this war on terrorism is going to take a while. And the American people must be patient. I'm going to be patient."