https://2009-2017.state.gov/documents/organization/119629.pdf
ALSO… https://fas.org/irp/doddir/dod/jp3_24.pdf
further results:
https://www.hsdl.org/?view&did=713599
https://slate.com/news-and-politics/2020/09/america-insurgency-chaos-trump-violence.html
https://www.trngcmd.marines.mil/Portals/207/Docs/TBS/B4S5499XQ%20CounterInsurgency%20Measures.pdf?ver=2016-02-10-114636-310
https://www.fdd.org/analysis/2020/06/23/us-insurrection-or-incipient-insurgency/
Better yet, there's a book by David Kilcullen where the word "challenge" is hypenated exactly like the quote Q uses. It's called Counterinsurgency.