Army Gen. Richard D. Clarke, commander of U.S. Special Operations Command, shakes the hand of a U.S. Navy SEAL candidate participating in Basic Underwater Demolition/SEAL training in San Diego, Aug. 2, 2019 at the end of “Hell Week.” Hell Week is a strenuous five-day crucible meant to test a candidate’s physical and mental toughness as part of the 63-week training required to become a Navy SEAL.