Sorry if this is a dup:

THINK "the football"

The football is carried by one of the rotating presidential military aides, whose work schedule is described by a top-secret rota (one from each of the five service branches). This person is a commissioned officer in the U.S. military, pay-grade O-4 or above, who has undergone the nation's most rigorous background check (Yankee White). These officers are required to keep the football readily accessible to the president at all times. Consequently, the aide, football in hand, is always either standing or walking near the president, including riding on Air Force One, Marine One, or the presidential motorcadewith the president.

Nuclear football - Wikipedia

https: //en.wikipedia.org/wiki/Nuclear_football

There are four things in the Football. The Black Book containing the retaliatory options, a book listing classified site locations, a manila folder with eight or ten pages stapled together giving a description of procedures for the Emergency Alert System, and a three-by-five-inch [7.5 × 13 cm] card with authentication codes. The Black Book was about 9 by 12 inches [23 × 30 cm] and had 75 loose-leaf pages printed in black and red. The book with classified site locations was about the same size as the Black Book, and was black. It contained information on sites around the country where the president could be taken in an emergency.