The proposed invasion of Afghanistan prompted protests with mass demonstrations in the days leading up to the official launch of the war on October 7, 2001. The continuation of the war in Afghanistan from 2001 to 2021 led to further protest and opposition to hostilities.

2001 On September 29, 2001, as many as 20,000 people demonstrated in Washington, D.C., United States, denouncing the impending United States invasion of Afghanistan. The protests were organized by the recently formed A.N.S.W.E.R. coalition. Thousands of protesters gathered at Meridian Hill Park (Malcolm X Park) and marched downtown, while elsewhere members of the Anti-Capitalist Convergence clashed briefly with police on their way to Edward R. Murrow Park, across from the headquarters of the World Bank and the IMF. Both groups of marchers converged on a rally at the Freedom Plaza.

In San Francisco almost 10,000 people converged on a park in San Francisco's Mission District to denounce the Bush administration's plans for military intervention in Afghanistan.

In Los Angeles roughly 2,500 protesters marched through the streets of Westwood.

In New York City 3,000 to 5,000 people took part in a peace march at Union Square.

In Barcelona, Spain, 5,000 people attended a rally and marched behind a banner that read: "No More Victims – For Peace." The protesters urged the Spanish government not to support any US military intervention or NATO retaliation.

On October 1, 2001, several thousand protesters demonstrated in New York City against any military offensive in response to the September 11 attacks in New York and near Washington. Sporting buttons that said "Don't Turn Tragedy into War" and "Our Grief Is Not a Cry for War", many protesters argued that the attacks were not an act of war but a criminal act to be dealt with through the international justice system.

On October 7, 2001, 10,000 to 12,000 people turned out in New York City to oppose the Bush administration's so-called war on terror. The group marched from Union Square to Times Square, cheering the police at the beginning of the march. The list of about twelve speakers was cut to three or four by the police, and they were herded at the end into a one-lane-wide "bullpen".

On October 13, 2001, more than 20,000 people joined the UK's biggest protest yet against military action in Afghanistan by the United States and its allies. Turn-out was twice as big as had been expected by organisers, with the noisy but peaceful march through London culminating in a rally at Trafalgar Square.

In Glasgow, Scotland, United Kingdom, around 1,500 people gathered in George Square for a rally against the military action in Afghanistan.

In Germany more than 25,000 protesters took to the streets in cities across the country. In Berlin, the largest demonstration drew 15,000 people to the central square in a rally that followed several marches throughout the city under the banner "No war – stand up for peace".

In Sweden the biggest demonstration took place in Gothenburg, where more than 2,500 people marched through the city.

In San Francisco 10,000 people took to the streets, while a rally in Washington Square in New York City attracted some 700 people.

In Australia, thousands of people demonstrated in the cities of Sydney, Melbourne, Perth and Adelaide.

On October 14, 2001, hundreds of thousands of peace protesters in Italy and India called for an end to the bombing of Afghanistan. More than 200,000 demonstrators took part in the peace march from the central Italian town of Perugia to Assisi, with protesters shouting "Stop the terrorism against Afghanistan", "We want peace not war", and chanting slogans attacking George W. Bush, the U.S. president.

In India, 70,000 people in Calcutta staged the biggest anti-war protest the country had ever seen. The protesters marched more than 7.5 miles through the city, entertained by performers who sang anti-war folk songs.

On November 10, 2001, after weeks of bombing, hundreds of protesters took to the streets across the United Kingdom to call for an end to the bombing of Afghanistan. In Bolton 250 people gathered in the town's Victoria Square. In York, about 200 protesters called for an end to the war during a two-hour demonstration. A vigil was held in London.

On November 18, 2001, thousands – police estimated 15,000, organizers estimated 100,000 – from all over the UK took part in a march in London to demonstrate again against the war in Afghanistan.

Many protesters waved placards reading "Stop the War" and "Not in My Name". As the demonstration fell during Ramadan, an element of prayer was included in the final rally to allow pious Muslims to observe their faith. Headlining speakers included human rights campaigner Bianca Jagger, Labour Party veteran Tony Benn, Labour MP George Galloway, and speakers of Muslim faith.

Member of Parliament Paul Marsden told the rally: !

Organiser Lindsey German said the bombing campaign had done nothing to tackle international terrorism.

At the time the protest was the largest peace demonstration in more than twenty years.Another coalition stands up to be counted, John Vidal, Monday November 19, 2001, The Guardian

2002 On April 20, 2002, 75,000 people marched in Washington, D.C. against U.S. militarism and foreign policy in the largest peace presence since the war began the previous fall. The April 20th Mobilization to Stop the War, a coalition of many groups, held a rally just south of the Washington Monument. Another protest focusing on perceived Israeli aggression against the Palestinian people was held near the White House, while a third protest focusing on the policies of the World Bank and the International Monetary Fund took place near the headquarters of those institutions. The three rallies then converged together in a march up Pennsylvania Avenue to the United States Capitol in the largest anti-war demonstration to take place in Washington since the Gulf War more than a decade ago.

Protesters denounced the bombing of Afghan civilians and carried signs and banners reading, "No blank check for endless war," "Criminals in the White House again" and "War without an end. Not in our name."

Some of the most moving speeches opposing the U.S.'s aggression were given by family members of victims of the terrorist attacks on September 11. Derril Bodley, who lost a daughter on September 11, said he had travelled to Afghanistan to call for an end to the "barbarous bombing campaign there." Just a few days after his daughter's death he spoke out against the possibility of war, saying, "Don't kill more innocent people in the name of my daughter." He said thousands were suffering and dying by the "perpetration of an aimless war."

Another speaker, Michael Ratner, a human rights lawyer and president of the Center for Constitutional Rights, denounced the conditions in which hundreds of prisoners captured in Afghanistan were being held at the U.S.'s military base in Guantanamo Bay, Cuba:

Another 15,000 to 20,000 people marched in San Francisco in a simultaneous protest on the West Coast, and demonstrations also took place in a number of other American cities.

2005 On August 17, 2005, over 1,000 people took part in a vigil in Minneapolis-Saint Paul to protest the wars in Afghanistan and Iraq. Organizers estimated the number at 1,200.

2006 On September 23, 2006, tens of thousands of people marched in Manchester, UK, against the presence of UK troops in Iraq and Afghanistan. Organizers estimated that about 30,000 people participated. Police put the figure at about 20,000. Speakers at a rally accused Prime Minister Tony Blair of following the United States into illegal wars in Iraq and Afghanistan.

On Saturday, October 28, 2006, thousands of protesters opposed to Canada's participation in the war in Afghanistan rallied in 40 cities and towns. Under the slogan "Support our troops, bring 'em home", as many as 500 demonstrators marched through downtown Ottawa to Parliament Hill to protest the military mission and demand the return of Canadian troops. Hundreds of protesters in Toronto and Montreal, 200 in Halifax, 100 in Edmonton, more than a 100 in Calgary, and more than 500 in Vancouver also took to the streets. Themes of the demonstrations included demands that the troops be brought home from Afghanistan and demands that the mission of the Canadian Forces in that country shift from a combat role to a peace keeping and humanitarian presence. Placards expressed such sentiments as "Build Homes Not Bombs," "Drop Tuition Not Bombs" and "Is This Really Peacekeeping". A total of 42 Canadian soldiers and one diplomat had so far been killed in Afghanistan.

Thousands of Pakistani tribesmen near the border with Afghanistan held a rally to protest against a missile attack that killed 80 people. About 5,000 tribesman held a protest march in Khar, the capital town of Bajaur tribal district, some 10 km south-east of the scene of the attack. The tribesmen said the dead, housed in a seminary, were merely students and that their families should be compensated. The effigies of U.S. president George Bush and Pakistani president Pervez Musharraf were paraded on mules before being set on fire. Since the U.S. air-strike on the school, thousands of local people have taken part in protests against Islamabad's alliance with the US.

2007 On February 23, 2007, hundreds of Canadians braved wind, rain, and snow to take part in rallies in cities across Canada to protest their country's military operation in Afghanistan, urging their government to bring Canadian troops home. In Vancouver, about 600 people rallied and marched through the downtown core. In Toronto, hundreds of protesters held a rally outside the U.S. consulate. Nearly 500 people marched through downtown Montreal. About 200 people gathered in front of city hall in Halifax. Demonstrations also took place in Edmonton, Quebec City, and St. John's, Newfoundland.

On April 30, 2007, thousands of Afghans staged a protest accusing U.S.-led coalition and Afghan troops of killing civilians in the western province of Herat. The protesters stormed a government district headquarters in Shindand, south of Herat city, where Western troops have a large base. The anti-U.S. protest came a day after an angry demonstration in eastern Nangahar province over the killing of civilians by coalition and Afghan forces there.

On June 22, 2007, protesters in Quebec City took part in a march to denounce the Canadian military involvement in Afghanistan and the deployment of additional troops to Kandahar province.

On Saturday October 27, 2007, rallies took place in 22 different Canadian cities to protest against the Canadian military mission in Afghanistan. In Montreal, around 300 protesters marched despite heavy rain, while protests in Toronto and Ottawa numbered around 200. At the time, 70 Canadian soldiers and one diplomat had been killed in Afghanistan.

2008 On March 15, 2008, thousands of protesters gathered in London and Glasgow to call for the withdrawal of UK troops from Iraq and Afghanistan. Police said there were 10,000 people on the streets in London but organizers put the crowds at between 30,000 and 40,000. In Glasgow, there 1,000 to 1,500 people took part in the march, according to police estimates.

On September 20, 2008, thousands of people in France and Germany took to the streets calling for soldiers deployed in Afghanistan to be brought home. More than 5,000 people took to the streets in the German cities of Berlin and Stuttgart to protest against the decision to prolong the deployment of German troops in Afghanistan. According to police estimates, over 3,300 people in Berlin, and over 2,000 people in Stuttgart took part in the rallies, while event organizers put the total figure at 7,000 people.