A massive sand storm cloud is close to enveloping a military camp as it rolls over Al Asad, Iraq, April 27, 2005. (Photo by Cpl. Alicia M. Garcia, U.S. Marine Corps/Reuters/U.S. Department of Defense)

A Sudanese girl with half painted face watches as protesters demonstrate outside the defense ministry compound in Khartoum, Sudan, April 25, 2019. (Photo by Umit Bektas/Reuters)

A visitor holds an Israeli-made rifle during the 8th International Land and Naval Defense system exhibition, in New Delhi, India, on February 6, 2014. (Photo by Anindito Mukherjee/Reuters)

Two female holidaymakers relax on an unidentified beach of England, September 21, 1940, as a soldier, eyes straight ahead, stands guard at a barrier built as a defense against possible invasion by Germany. (Photo by AP Photo)

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 miniature sculpture in the shape of a home, created by self-taught artist Jadranko Djordjevic on a graphite pencil, is seen in Tuzla, Bosnia and Herzegovina April 26, 2016. (Photo by Dado Ruvic/Reuters)

A hot air balloon in tortoise shape flies in the air during the Tazaungdaing air balloon festival in Pyin Oo Lwin, Myanmar, 25 November 2015. During the festival, hot air balloons made of multicolored papers and hung with paper lanterns, fireworks and fire sticks are exploded in mid-air. (Photo by Hein Htet/EPA)

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)