This beard phenomenon came about after 9/11 and crept into American culture. It’s quite bizarre.
I do recall that. Early in our involvement in Afghanistan in late 2001/early 2002, there were a number of news articles and some debate in the military regarding our special forces operatives and how they were wearing beards in order to ingratiate themselves with the indigenous Afghans with whom they were living and fighting. Coincidentally or not, I saw a lot of beards start sprouting around that time.