In this Friday, February 27, 2015 photo, an Israeli high-school senior preparing to join the Israeli military later this year participates in a privately run training camp for military combat fitness near Yakum, central Israel. With a mandatory three-year military service looming after graduation, teenage boys, and increasingly girls too, are gearing up for the draft, getting into shape and trying to improve their chances of acceptance into elite combat units. (Photo by Oded Balilty/AP Photo)

“The Boeing X-45 unmanned combat air vehicle is a concept demonstrator for a next generation of completely autonomous military aircraft, developed by Boeing's Phantom Works. Manufactured by Boeing Integrated Defense Systems, the X-45 was a part of DARPA's J-UCAS project”. – Wikipedia

Photo: Two X-45A Unmanned Combat Air Vehicles (UCAV) are shown to members of the news media July 11, 2002 at Edwards Air Force Base, California. The X-45A, developed by The Defense Advanced Research Projects Agency and the Boeing Company, is the first unmanned system designed from inception for combat missions. (Photo by David McNew/Getty Images)

Ukrainian serviceman fires with a heavy machine gun during a combat with Russia-backed separatists on the front line near Gorlivka, Donetsk Region on September 28, 2019. (Photo by Anatolii Stepanov/AFP Photo)

A Wiesel combat vehicle of the German Bundeswehr armed forces takes part in a demonstration for visitors prior to military exercises on September 28, 2011 near Munster, Germany. The Bundeswehr has instituted far-reaching changes in recent years, including an end to compulsory military service. (Photo by Sean Gallup/Getty Images)

A French soldier stands near a military combat command vehicle on display at The Defence and Security Exhibition on September 13, 2011 in London, England. ExCeL London is hosting the exhibition with hundreds of manufacturers from all over the world displaying their hardware. (Photo by Peter Macdiarmid/Getty Images)

Long row of shiny new Flying Fortresses, part of huge reserves being built up in Britain for D-Day, stands by to be flown to combat units as replacements, May 25, 1944. (Photo by AP Photo)

Trainees of the Tianjiao Special Guard/Security Consultant bodyguard training camp watch their instructor use a scarf to cover a student's head during a demonstration of close-quarter combat skills at a special course on flight safety inside a scale model of a passenger jet at a flight attendant training centre on the outskirts of Beijing, March 18, 2014. Inspired by the missing Malaysia Airlines Flight MH370, the company wanted to emphasize the importance of aviation safety by teaching their trainees emergency evacuation procedures and close-quarter combat skills to handle situations such as natural disasters and plane hijacks, according to the company. (Photo by Jason Lee/Reuters)

Ireland's Philip Mulpeter, left, is kicked by Brazilian Vitor Nobrega during their welterweight mixed martial arts bout of International Pro Combat at the Estoril Casino in Estoril, near Lisbon, Portugal, Monday, January 26, 2015. Nobrega defeated Mulpeter. (Photo by Francisco Seco/AP Photo)