U.S. Marines, left, and South Korean Marines, wearing blue headbands on their helmets, take positions after landing on the beach during the joint military combined amphibious exercise, called Ssangyong, part of the Key Resolve and Foal Eagle military exercises, in Pohang, South Korea, Saturday, March 12, 2016. North Korea said Saturday its military is ready to pre-emptively attack and “liberate” the South in its latest outburst against the annual joint military drills by the United States and South Korea. (Photo by Kim Jun-bum/Yonhap via AP Photo)

Hotel staff practice self-defence skills after a training session given by team member of Special Weapons and Tactics (SWAT) team, in Hangzhou, Zhejiang province, April 7, 2016. (Photo by Reuters/Stringer)

Ride operator Van Mai wears a face mask against the spread of the coronavirus while working at the Playland amusement park at the Pacific National Exhibition, in Vancouver, British Columbia, Friday, July 10, 2020. (Photo by Darryl Dyck/The Canadian Press via AP Photo)

Street vendosr prepare grilled pigs to sell for the Chinese New Year celebrations at a market in Phnom Penh, Cambodia, 11 February 2021. Chinese people around the world celebrate the Lunar New Year, also known as the Spring Festival, which marks the year of the Ox. (Photo by Kith Serey/EPA/EFE)

Activists stage a theatrical play where gay people are restrained by others wearing masks depicting Russian President Vladimir Putin, during a protest against Russia's new law on gays, in central London, Saturday, August 10, 2013. Hundreds of protesters, called for the Winter 2014 Olympic Games to be taken away from Sochi, Russia, because of a new Russian law that bans “propaganda of nontraditional sexual relations” and imposes fines on those holding gay pride rallies. (Photo by Lefteris Pitarakis/AP Photo)

Kazuo Hirai, President and Group CEO of Sony Computer Entertainment America, presents the Playstation Vita at the Sony Playstation media briefing on the eve of the Electronic Entertainment Expo (E3) on June 6, 2011 in Los Angeles, California. More than 45,000 people are expected to attend the annual three-day convention to see the latest games and announcements from the gaming industry. (Photo by David McNew/Getty Images)

A U.S. Army B-24 Liberator Bomber is hailed by a ground crewman as it takes off over a line of shark- nosed fighter planes at an advanced base in China on a mission on October 10, 1943, to bomb Japanese installations. (Photo by AP Photo)

A dancer performs during the Gymnastics Rio Gala on Day 12 of the 2016 Rio Olympic Games on August 17, 2016 in Rio de Janeiro, Brazil. (Photo by Clive Brunskill/Getty Images)