Two Czech Gripen fighter planes demonstrate a flight interception of a Belgian air force transport plane over the Czech Republic, as part of NATO drills on September 12, 2018. (Photo by Francois Lenoir/Reuters)

Soldiers on exercise in Kenya. The image, by Sergeant Dek Traylor, is among the section winners in the UK Army Photographic Competition 2018. (Photo by Sergeant Dek Traylor/PA Wire Press Association)

Russian police cadets march during general rehearsal of the Victory Day parade on the Dvortsovaya Square in St. Petersburg, Russia, 07 May 2021. The military parade marking the 76th anniversary of the victory over Nazi Germany in the World War II will take place on the Dvortsovaya Square on 09 May 2021. (Photo by Anatoly Maltsev/EPA/EFE)

A British RAF Typhoon aircraft escorts a C130 transport plane on its way to Jordan for an airdrop of paratroopers from the U.K.'s 16th Air Assault Brigade as part of an exercise conducted jointly with Jordanian soldiers on Wednesday, June 23, 2021. (Photo by Petros Karadjias/AP Photo)

Artists wear colourful “deconfinement hats” made of paper mache and inspired by Song dynasty headwear, for social distancing, at 59 Rivoli gallery in Paris as it prepares a general reopening later in the week, following the outbreak of the coronavirus disease (COVID-19) in France, June 3, 2020. (Photo by Benoit Tessier/Reuters)

Japanese women wearing “yukata” casual summer kimono take selfies at Asakusa district in Tokyo, Japan, 13 September 2020. Asakusa is one of Tokyo's most-visited areas and is usually crowded with tourists. In Japan, the numbers of visitors from abroad fell by 99.9 percent from a year earlier in July due to the ban for entries of foreign visitors amid the coronavirus pandemic. (Photo by Franck Robichon/EPA/EFE)

Men wear masks as they sit in the metro in Prague, Czech Republic, 17 March 2020. According to media reports, the Czech government decided to impose a two-week quarantine in the country on the evening of 15 March, and ban all international travel from 16 March 2020. Currently 383 cases of the coronavirus SARS-CoV-2, which causes the Covid-19 disease, have been officially confirmed in Czech Republic. (Photo by Martin Divisek/EPA/EFE)

Noah, 10, cools himself off in his garden during hot weather in Hertford, Britain, June 25, 2020. The UK is experiencing a summer heatwave, with temperatures in many parts of the country expected to rise above 30°C and weather warnings in place for thunderstorms at the end of the week. (Photo by Andrew Couldridge/Reuters)