You missed out on the other incentive - there's plenty of opportunities to sell "security" (ie comfort blankets) to scared people. Huge numbers of exDHS (and indeed ex generals) end up paid by security / military companies selling expensive stuff to the government. This is an active incentive to scare people.
Don't forget that even when not directly paid by defense contractors and the like, many government officials simply own stock in these and other corporations that stand to benefit for an increased need for security.
