US Army Parachute Team Golden Knights perform a precision drop to commemorate the 50th anniversary of the end of the Vietnam War, above West Potomac Park in Washington, DC, USA, 11 May 2023. The performance is one of many activites being held on the National Mall over three days to honor Vietnam War veterans and their families and to commemorate the 50th anniversary of when the last US combat troops left South Vietnam in 1973. (Photo by Michael Reynolds/EPA/EFE)

Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

Fossilized whale bones are on display outside the Wati El Hitan Fossils and Climate Change Museum, a UNESCO natural World Heritage site, on the opening day, in the Fayoum oasis, Egypt, Thursday, January 14, 2016. Egypt has cut the ribbon on the Middle East's first fossil museum housing the world's largest intact skeleton of a "walking whale" in an attempt to attract much-needed tourists driven off by recent militant attacks. The construction of the much-hyped Fossils and Climate Change Museum was covered a 2 billion euros (2. 17 billion dollars) grant from Italy, according to Italian Ambassador Maurizio Massari. Its centerpiece is an intact, 37-million-year-old and 20-meter-long skeleton of a legged form of whale that testifies to how modern-day whales evolved from land mammals. The sand-colored, dome-shaped museum is barely discernible in the breathtaking desert landscape that stretches all around. (Photo by Thomas Hartwell/AP Photo)

Pakistani laborers transport the front portion of a vehicle using a handcart at a road in Peshawar, Pakistan, Monday, August 3, 2015. (Photo by Mohammad Sajjad/AP Photo)

Japan's delegation gather to sign the formal surrender document on the U.S. Navy battleship USS Missouri in Tokyo Bay in a September 2, 1945 file photo. (Photo by Reuters/US Navy)

A Palestinian protester uses a sling shot to throw stones towards Israeli security forces during clashes on the Israeli border Eastern Gaza City, Friday, November 6, 2015. (Photo by Adel Hana/AP Photo)

French street artist OakOak produces creative works of art that use the characteristics of a location such as a light post, road sign and even a crack in the wall as inspiration but also as key elements in the work. (Photo by OakOak)

“DC3 Wreck”. A capture of a US military DC3 plane wreck at the southern black beach in Iceland. Photo location: Iceland. (Photo and caption by Naian Feng/National Geographic Photo Contest)