Interesting...
https://www.newsweek.com/us-army-spend-500-million-training-soldiers-fight-underground-997906#:~:text=The%20Department%20of%20Defense%20(DOD,news%20site%20Military.com%20reported
https://www.newsweek.com/us-army-spend-500-million-training-soldiers-fight-underground-997906#:~:text=The%20Department%20of%20Defense%20(DOD,news%20site%20Military.com%20reported