Members of the Moroccan Royal Armed Forces Rescue and Relief Unit take part in a biochemical simulation organized by the US Defense Threat Reduction Agency (DTRA) as part of the “African Lion” military exercise, in the port of Agadir, on June 15, 2021. (Photo by Fadel Senna/AFP Photo)

Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

Most pet cats will become timid or defensive when outdoors, but not Millie – after being adopted by her mountain-climbing owner Craig Armstrong, Millie has become a feline hiking and mountain-climbing legend.

A flight deck crew prepares to launch a F18 Super Hornet from the deck of the USS Eisenhower off the coast of Virginia, December 10, 2015 in the Atlantic Ocean. US Defense Secretary Ash Carter visited the carrier with India's Minister of Defense Manohar Parrikar to demonstrate US Navy aircraft carrier flight operations. (Photo by Mark Wilson/Getty Images)

Guns decorated with gold and jewellery are displayed in the Drugs Museum, used by the military to showcase to soldiers the lifestyles of Mexican drug lords, at the headquarters of the Ministry of Defense in Mexico City, October 14, 2016. (Photo by Henry Romero/Reuters)

A demonstrator confronts riot police during a rally in defense of the nationalization of lithium reserves in the country, in Santiago, Chile on January 29, 2018. (Photo by Pablo Sanhueza/Reuters)

General view of a clash after the match of the Egyptian Premier League between Pyramids FC and Zamalek at the 30 June Air Defense Stadium in Cairo, Egypt on April 23, 2019. (Photo by Amr Abdallah Dalsh/Reuters)

Self-employed pedicab driver Danilo Guerra, 25, uses his mobile phone as he waits for clients in downtown Havana April 12, 2016. (Photo by Alexandre Meneghini/Reuters)