Opposition to the War in Afghanistan (2001–2021) stems from numerous factors, including the view that the United States invasion of Afghanistan was illegal under international law and constituted an unjustified aggression, the view that the continued military presence constitutes a foreign military occupation, the view that the war does little to prevent terrorism but increases its likelihood, and views on the involvement of geo-political and corporate interests. Also giving rise to opposition to the war are civilian casualties, the cost to taxpayers, and the length of the war to date.