A new documentary, "Against All Enemies," explores the link between military veterans and extremism. Producer Ken Harbaugh told Insider veterans looking for purpose are at risk of radicalization. Advertisement Of the more than 1,000 people who were charged with a crime for their participation in the January 6 attack on the Capitol, nearly 1 in 5 was a US military veteran. While leaders of extremist groups like the Proud Boys and Oath Keepers were ultimately convicted for seditious conspiracy for their deliberate attempts to breach the Capitol, critics argue their influence on military veterans — and the subsequent impact on...