I think the 500,000 is an underestimation. Studies show it was over 1 million in Iraq alone, violent deaths that occurred directly and indirectly due to the war.
Another way to look at it. Imagine if the $6 trillion was spent on infrastructure projects, clean water projects, education, healthcare, housing, in the US and around the world where needed.
US has spent almost $6 trillion on wars since 2001
By Trévon Austin
17 November 2018
A report released by the Watson Institute of International & Public Affairs at Brown University indicates the total sum spent on the “war on terror” is much larger than previously suggested. Professor Neta C. Crawford, the author of the study, revealed that the US government is set to spend nearly $6 trillion on post-9/11 wars by the end of the 2019 fiscal year.
In March, the Department of Defense (DoD) released a report stating the military had spent $1.5 trillion on the wars. However, the Brown University report notes the DoD’s numbers were a conservative estimate that also failed to take into account spending across other federal departments. The new estimate not only includes expenditures from the Department of Homeland Security (DHS), budget increases, and medical costs for veterans, but also interest on money borrowed to pay for the wars.
Including indirect war spending, the total amount of spending allocated since 2001 will be $4.6 trillion by the end of 2019. The report also estimates the government will be obligated to spend around $1 trillion for the future care of post 9/11 veterans until 2059. The total sum amounts to a staggering $5.993 trillion.
The study warns that continuing the multitude of US war and interventions for another four years would cost an additional $808 billion, even if the United States were to stop such actions by 2023. The accumulated costs would likely exceed the estimated $6.7 trillion because the number of veterans will continue to grow as long as the US continues military operations. https://www.wsws.org/en/articles/2018/11/17/cost-n17.html
