According to recent research, the wars launched by the United States in the Middle East and North Africa in the aftermath of the September 11 attacks have directly or indirectly killed at least 4.5 million people and displaced millions more.

The study by Brown University Watson Institute's Costs of War project detailed how almost one million people have directly died as a result of conflicts in Afghanistan, Iraq, Pakistan, Syria, Yemen, Libya, and Somalia.

Read more: 20 years of war: How much did the US war in Iraq, Syria cost? 

The report released on May 15 noted that at least 3.6 to 3.7 million of the casualties were "indirect" deaths caused by a variety of factors such as failed economies, extreme poverty, malnutrition, disease, destroyed health infrastructure, environmental contamination, and reverberating trauma and violence.

After more than two decades, the number of direct and indirect war victims from ongoing worldwide conflicts continues to rise, according to the research.

“These wars are ongoing for millions around the world who are living with and dying from their effects,” it said, detailing how women and children “suffer the brunt of the impact.”

“A death from hunger mostly occurs at some distance from this attention to spectacle and it may happen months or years after war disrupts access to food. Often, people affected by war are displaced and transient, making them hard to track.”

The report added that “indirect deaths are devastating, not least because so many of them could be prevented, were it not for war."

The research also stated that it is difficult to distinguish between indirect war death causes and those that may have happened in areas where people already face high rates of poverty, sickness, and starvation. 

It singled out the United States for its participation in several post-9/11 wars, notably the losses in Afghanistan over the previous two decades.

Despite the fact that the US conducted a catastrophic withdrawal from Afghanistan in 2021,   Afghans are "suffering and dying from war-related causes at higher rates than ever."

The study also urged Washington to make reparations for the harm caused by post-9/11 wars, stating that "reparations, though not easy or cheap, are imperative."

"The report's goal is to build greater awareness of the fuller human costs of these wars and support calls for the United States and other governments to alleviate the ongoing losses and suffering of millions in current and former war zones," it said.

Stephanie Savell, the report's author and co-director of the Consequences of War project, also stated that "there are reverberating costs, the human cost of war, that people in the United States, for the most part, don't really know enough about or think about."

According to the author, the researchers used the Geneva Declaration Secretariat's average ratio of four indirect deaths for every one direct death, and while that ratio may be lower in Iraq, it would be higher in Yemen or Afghanistan, so the ratio was deemed accurate to arrive at the "reasonable and conservative" estimate of 4.5-4.6 million.

On this day, 20 years ago, #US forces started to bomb #Iraq signaling the launch of their invasion of the country. Millions of Iraqis suffered from the ruthless violence of US forces, notably in the infamous #AbuGhreib prison. pic.twitter.com/UA4MWduXpp

— Al Mayadeen English (@MayadeenEnglish) March 19, 2023