In this October 6, 2018, photo, a craftsman makes daggers or “Jambiyya” in Yemeni Arabic, made out of remains of missiles, at his workshop, in Hajjah, Yemen. Missiles raining on Yemen from the jets of the Saudi-led coalition fighting Houthi rebels are killing thousands of civilians and militiamen alike, but amid crashing economy, some Yemenis see the bright side of it: they make daggers out of the fragments of the missiles for ordinary men traditionally wear for prestige and a show of courage. (Photo by Hammadi Issa/AP Photo)

In this March 7, 1991 file photo, a U.S. Marine patrol walks across the charred oil landscape near a burning well during perimeter security patrol near Kuwait City. Twenty five years after the first U.S. Marines swept across the border into Kuwait in the 1991 Gulf War, American forces find themselves battling the extremist Islamic State group, born out of al-Qaida, in the splintered territories of Iraq and Syria. The Arab allies that joined the 1991 coalition are fighting their own conflicts both at home and abroad, as Iran vies for greater regional power following a nuclear deal with world powers. (Photo by John Gaps III/AP Photo)

In this photo taken Wednesday, December 5, 2018, a woman who scavenges recyclable materials from garbage for a living is seen through a cloud of smoke from burning trash, surrounded by Marabou storks who feed on the garbage, at the dump in the Dandora slum of Nairobi, Kenya. As the world meets again to tackle the growing threat of climate change, how the continent tackles the growing solid waste produced by its more than 1.2 billion residents, many of them eager consumers in growing economies, is a major question in the fight against climate change. (Photo by Ben Curtis/AP Photo)

Gymnast Ahmad al-Sawas performs gymnastic moves near damaged buildings in the rebel-held Bustan al-Qasr neighbourhood of Aleppo, Syria March 26, 2016. As Syrian gymnast Ahmad al-Sawas watched his country fall apart, his Olympic dream collapsed too. The last national champion before the fighting began, he knew that supporting the anti-government side in the five-year-old civil war would prevent him from being selected for the Rio Games. (Photo by Abdalrhman Ismail/Reuters)

The unromantic gypsies. Children boxing in a gypsy camp in Kent, England on July 1, 1951. Like all boys these gypsy lads like to try their hand at boxing. Encouraged by their friends they fight it out on Corke's Meadow. Few Romanies now live a life of wandering romance. Most are like the three hundred squatters of Corke's Meadow, Kent, which is part of a “gypsy problem” that involves about 100,000 today. Of those about 25,000 can be rightly called gypsies, the rest are Mumpers and Posh-rats and Hobos. Corke's Meadow has both kinds. “Picture Post” cameraman Bert Hardy photographs the Corke's Meadow gypsies in their encampment. (Photo by Hulton-Deutsch Collection/Corbis via Getty Images)

“Two Brothers”. We found about 20 lions eating a buffalo. When the male leaved the group we anticipated him to take photos. It is 8AM, light is perfect and the position too. The lion stops and looks down from the hill, another lion is coming up, it stiffens, I think that will be a fight, i'm tense, the camera is OK, the shots previously made perfect. The two meet, looking directly into their eyes, they sniff, rub against their heads, the tension drops, they start walking with the same step as when they were puppies, they are two brothers. Photo location: Masai Mara, Kenya. (Photo and caption by Massimo Mei/National Geographic Photo Contest)

Yussef Saluta (R), 20, an Israeli Arab soldier from the Desert Reconnaissance battalion takes part in a drill near Kissufim in southern Israel November 29, 2016. A battalion of soldiers crawls across the desert sand with assault rifles cocked. It's a routine exercise, but these are no ordinary troops – they are Arabs who have chosen to fight for the Jewish state. (Photo by Amir Cohen/Reuters) (Photo by Amir Cohen/Reuters)

Police officers detain an opposition protester during a May Day rally in Saint Petersburg, Russia on May 1, 2019. Labor Day or May Day is observed all over the world on the first day of the month of May to celebrate the economic and social achievements of workers and fight for laborers rights. (Photo by Igor Russak/Reuters)