Hegseth on Tuesday cited the "fog of war" in defending the follow-up strike.
The White House acknowledges that a second strike was ordered on a boat already hit by the military in the Caribbean Sea.
An annual tradition was back another year in the city as the Chicago Thanksgiving Parade marched through the Loop. Other holiday events and food giveaways were also held across the city and suburbs, including special meals for Navy recruits.
Members of the U.S. military have the legal right to refuse orders they believe are unlawful, but they risk violating military laws of obedience if the order is in fact lawful, experts in military law say.
DHS has left its "Operation Midway Blitz" command center at Naval Station Great Lakes, city officials said. Texas National Guard members and Border Patrol Cmdr. Greg Bovino also vacated the Chicago area this week.