The September 11, 2001 attacks ushered in an era of increased surveillance, human rights violations and mass displacements globally, with the social and economic fallout likely to continue for decades, activists and academics have said.
The 9/11 attacks triggered new security laws in the United States, and an extended campaign to root out terrorism worldwide which has had far-reaching consequences from the rise of surveillance technologies to refugee crises.
A recent report by three US activist groups has claimed that tech giants like Amazon, Google and Microsoft have made vast profits from US government contracts since the 9/11 attacks.
Nearly 3,000 people were killed in the attacks on US soil.
The Costs of War project at Brown University has calculated the actual cost incurred by the United States of America, both in monetary as well as humanitarian terms. Here's is a look at that:
• The vast economic impact of the US post-9/11 wars goes beyond the Pentagon's "Overseas Contingency Operations", according to Costs of War project. It led to an expenditure of more than $8 trillion and caused about 900,000 deaths, according to its estimates.
• At least 37 million people have fled their homes in the eight most violent wars the US military has launched or participated in since 2001 - including Afghanistan, Iraq, Syria, Libya and Yemen, the Costs of War project said.
• The true figure is likely to be as high as 59 million, the researchers said, noting the "incalculable harm" done to individuals, families, towns, regions, as well as to entire countries physically, socially, emotionally, and economically.
• The US spent $2.313 trillion in operations in both Afghanistan and Pakistan since launching its military mission after the attacks in 2001, the researchers said. This was part of the overall budgetary costs it incurred in the post-9/11 missions.
• They say the amount does not include funds that the US government is obligated to spend on lifetime care for American veterans of this war, nor does it include future interest payments on money borrowed to fund the war.