A fighter jet flies above as Ukrainian soldiers sit on an armoured personnel carrier in Kramatorsk, in eastern Ukraine April 16, 2014. Ukrainian government forces and separatist pro-Russian militia staged rival shows of force in eastern Ukraine on Wednesday amid escalating rhetoric on the eve of crucial four-power talks in Geneva on the former Soviet country's future. (Photo by Marko Djurica/Reuters)

Indian Air Force (IAF) cadets march during a graduation parade at the Air Force Academy in Dundigal, on the outskirts of Hyderabad, India, Saturday, June 20, 2020. A total of 123 flight cadets including 19 women officers were commissioned as flying officers on Saturday on successful completion of their training, a press release said. (Photo by Mahesh Kumar A./AP Photo)

South Korean military soldiers take part in the South Korea and U.S. joint military exercise to commemorate the 63th Korea Armed Forces Day at the Seungjin firing drill ground on September 30, 2011 in Pocheon, South Korea. The exercise is intended to prepare the South Korean defence force for any potential action from North Korea. (Photo by Chung Sung-Jun/Getty Images)

Members of Hashid Shaabi or Popular Mobilization Forces (PMF) fire towards Islamic State militant positions in west of Mosul, Iraq, December 28, 2016. (Photo by Reuters/Stringer)

An Israeli Air Force F-35 fighter jet flies during an aerial demonstration at a graduation ceremony for Israeli airforce pilots at the Hatzerim air base in southern Israel December 29, 2016. (Photo by Amir Cohen/Reuters)

An empty cell block is pictured within Joint Task Force Guantanamo's Camp VI at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. (Photo by Lucas Jackson/Reuters)

U.S. President Donald Trump boards Air Force One to depart for Vietnam from Beijing Airport in Beijing, China on November 10, 2017. (Photo by Jonathan Ernst/Reuters)

Libyan forces allied with the U.N.-backed government fire weapons during a battle with IS fighters in Sirte, Libya, July 21, 2016. (Photo by Goran Tomasevic/Reuters)