A United States Air Force (USAF) F-15 fighter jet travels at low altitude through the “Mach Loop” series of valleys near Dolgellau, north Wales on June 26, 2018. The Mach Loop valleys, situated between Dolgellau and Machynlleth, are regularly used by the military for operational low flying training which can take place as low as 76 metres from the nearest terrain. The USAF regularly use the loop to practice low-altitude flight, which confuses radar systems. (Photo by Oli Scarff/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)

Members of Saudi security forces take part in a military parade in preparation for the annual Haj pilgrimage in the holy city of Mecca September 17, 2015. (Photo by Ahmad Masood/Reuters)

Pfc. Sebastian Rodriguez, machine gunner, Weapons Platoon, Lima Company, 3rd Battalion, 3rd Marine Regiment, Marine Rotational Force – Darwin, fires an M240 machine gun during a night squad-attack exercise, here, May 22, 2013. (Photo by Sgt. Sarah Fiocco/U.S. Marines)

In this photo illustration, an endangered Chinese box turtle which hatched at Bristol Zoo is placed on a box of matches on August 12, 2008 in Bristol, England. It weighs just 15 grams and measures around 4cm long whereas an adult box turtle weighs around 800 grams, measures around 16 cm long and can live up to 50 years. Chinese box turtles are hunted for their meat for use in medicine or as pets and have been listed as endangered on the International Union for Endangered Species Red List. (Photo by Matt Cardy/Getty Images)

A sculpture is displayed at the Olympic Sculptures Exhibition at the Sculpture Park September 4, 2006 in Changchun of Jilin Province, China. (Photo by China Photos/Getty Images)

A model displays the collection of Italian luxury brand Diesel at its China's first flagship shop unveiling ceremony, at Henglong Plaza on November 26, 2005 in Shanghai, China. (Photo by China Photos/Getty Images)