[1]The U.S. post-9/11 wars have forcibly displaced at least 38M people
   [pdf] ([2]brown.edu)

References

   1. https://watson.brown.edu/costsofwar/files/cow/imce/papers/2021/Costs of War_Vine et al_Displacement Update August 2021.pdf
   2. https://news.ycombinator.com/from?site=brown.edu