A flight deck crew member stands on the USS Ronald Reagan, off the coast of Queensland, Australia, 12 July 2019. The Nimitz-class aircraft carrier USS Ronald Reagan is taking part in Talisman Sabre 2019, which is a bilateral training exercise involving 34,000 military personnel from Australia, the United States, New Zealand, Canada, the United Kingdom and Japan. (Photo by Darren England/EPA/EFE)





In this September 17, 2015, file photo, an Emirati gunner watches for enemy fire from the rear gate of a United Arab Emirates Chinook military helicopter flying over Yemen. (Photo by Adam Schreck/AP Photo/File)





Servicemen of the Belarusian Special Task Forces take qualification tests to earn the maroon beret at the Valowshchyna range in Minsk Region, Belarus on September 24, 2019. (Photo by Natalia Fedosenko/TASS)





In this March 12, 2016, file photo, Marines of the U.S., left, and South Korea, wearing blue headbands on their helmets, take positions after landing on a beach during the joint military combined amphibious exercise, called Ssangyong, part of the Key Resolve and Foal Eagle military exercises, in Pohang, South Korea. Ahead of the second summit between U.S. President Donald Trump and North Korean leader Kim Jong Un, some observers say there is an uncertainty over the future of the decades-long military alliance between Washington and Seoul. (Photo by Kim Jun-bum/Yonhap via AP Photo)





A Ukrainian serviceman shouts with grenade launcher during combat with Russia-back separatists near Gorlivka, Donetsk region on May 23, 2019. (Photo by Anatolii Stepanov/AFP Photo)





Fighters loyal to the internationally recognised Government of National Accord (GNA) run for cover during clashes with forces loyal to strongman Khalifa Haftar south of the capital Tripoli's suburb of Ain Zara, on April 25, 2019. (Photo by Fadel Senna/AFP Photo)





A Russian National Guard officer takes part in Cooperation-2019, a joint Russian-Chinese counter-terrorism drill, at the Gorny training ground in Novosibirsk Region, Russia on October 15, 2019. (Photo by Kirill Kukhmar/TASS)





A Ukrainian serviceman guards a position near the front line as the conflict continues, in Mariinka, Donetsk region, eastern Ukraine, Saturday, April 20, 2019. The two presidential candidates for election on Sunday are pressing separate solutions for a resolution of the conflict in eastern Ukraine, where fighting with Russia-backed separatist rebels has killed more than 13,000 people since 2014. (Photo by Evgeniy Maloletka/AP Photo)





A Canadian Forces member is seen in a mirror while riding in a Light Armoured Vehicle (LAV) through the flooded Constance Bay area in Ottawa, Ontario, Canada, April 30, 2019. (Photo by Chris Wattie/Reuters)





A fighter loyal to Libya's U.N.-backed government (GNA) gestures during clashes with forces loyal to Khalifa Haftar on the outskirts of Tripoli, Libya on May 25, 2019. (Photo by Goran Tomasevic/Reuters)





A marine from Russia fires as he takes part in the International Army Games 2019 at the at Khmelevka firing ground on the Baltic Sea coast in Kaliningrad Region, Russia on August 8, 2019. (Photo by Vitaly Nevar/Reuters)





U.S. Army soldiers from the 2nd Platoon, B battery 2-8 field artillery, fire a howitzer artillery piece at Seprwan Ghar forward fire base in Panjwai district, Kandahar province southern Afghanistan, June 12, 2011. (Photo by Baz Ratner/Reuters)





A Kurdish fighter from the People's Protection Units (YPG) fires his rifle at Islamic State militants as he runs across a street in Raqqa, Syria, July 2017. (Photo by Goran Tomasevic/Reuters)





Turkey-backed Syrian rebel fighters assist their injured fellow fighter near the border town of Tal Abyad, Syria, October 24, 2019. (Photo by Khalil Ashawi/Reuters)





In this July 13, 2007, file photo, Tamil Tiger fighters take part in a training of breaking through outer defense lines of a military camp, in an undisclosed location deep in Tiger controlled territory, northeast of Colombo, Sri Lanka. The April 21, 2019 deadly Easter attacks in Sri Lanka are a bloody echo of decades past in the South Asian island nation, when militants inspired by attacks in the Lebanese civil war helped develop the suicide bomb vest. Over nearly 30 years of civil war, the Tamil Tigers would launch more than 130 suicide bomb attacks, making them the leading militant group in such assaults at the time. (Photo by Gemunu Amarasinghe/AP Photo/File)





U.S. Army Sgt. Dylan Henry, of the 75th Ranger Regiment, fires a machine gun mounted on a vehicle during the Best Ranger competition Friday, April 12, 2019, in Fort Benning, Ga. (Photo by John Bazemore/AP Photo)





This undated photo posted Monday, August 26, 2019, on the Thailand Royal Office website shows Major General Sineenatra Wongvajirabhakdi, the royal noble consort of King Maha Vajiralongkorn. She was bestowed the title of Chao Khun Phra Sineenatra Bilasakalayani by King Maha Vajiralongkorn during a ceremony in late July. In May the king named another woman Suthida Vajiralongkorn Na Ayudhya as the queen of Thailand. (Photo by Thailand Royal Office via AP Photo)





A helicopter gunner waits for takeoff at a US military base at an undisclosed location in Eastern Syria, Monday, November 11, 2019. The deployment of the mechanized force comes after US troops withdrew from northeastern Syria, making way for a Turkish offensive that began last month. (Photo by Darko Bandic/AP Photo)





U.S. Marine Jacob Kostelecky (L) keeps watch with a Mexican Marine during operations in urban terrain as they train side-by-side during a Rim of the Pacific Exercise (RIMPAC) at Camp Pendleton, California, U.S. July 9, 2018. (Photo by Mike Blake/Reuters)





Kurdish female fighters of the Women's Protection Unit (YPJ) take part in a military parade as they celebrate victory over the Islamic state, in Qamishli, Syria on March 28, 2019. (Photo by Rodi Said/Reuters)