Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

These Arab recruits line up in a barracks square in the British Mandate of Palestine, on December 28, 1940, for their first drill under a British solider. Some 6,000 Palestinian Arabs signed up with the British Army during the course of World War II. (AP Photo)

The Baby Nager dragon, from DreamWorks’ new “How to Train Your Dragon” Live Spectacular touring musical, shows off it’s colors outside of the New York Public Library. (Photo by Mark Von Holden)

An ice swimming enthusiast dressed as Neptune takes to the frigid waters of Orankesee lake during the 27th annual "Winter Swimming in Berlin" on January 8, 2011 in Berlin, Germany. A local swimmers' group called the “Berlin Seals” invite ice swimmers from across Germany and abroad to the annual event. Members claim ice swimming is good for the body's blood circulation. (Photo by Sean Gallup)

An effigy representing Judas Iscariot burns as some people wearing masks watch during Holy Week in the Catia neighborhood of Caracas, Venezuela, Sunday, April 4, 2021. The Burning of Judas is an Easter-time ritual in many communities, where an effigy of Judas Iscariot is hanged on Good Friday, then burned on Easter Sunday. (Photo by Matias Delacroix/AP Photo)

Protesting women shout slogans during a demonstration against sexual violence in front of the governor's mansion in San Juan, Puerto Rico on May 3, 2021. The demonstrators denounce the inaction and slowness of the state in implementing the executive order declaring a state of emergency against gender-based violence. (Photo by Ricardo Arduengo/AFP Photo)

An Israeli 155mm self-propelled howitzer, loaded on a trailer, arrives at a position along the Israel-Gaza border on May 13, 2021. Israel deployed additional troops to Gaza's border as the military conflict with Palestinian Islamists raged on, while inside Israel security forces scrambled to contain deadly riots between Jews and Arabs. (Photo by Emmanuel Dunand/AFP Photo)

Afghan children watch the Kabul view as they stand near to a victim's grave who lost her life in the recent attack on Sayyid al-Shuhada school in west Kabul, Afghanistan, 11 May 2021. Following a terrorist attack on a girls school in Kabul on 08 May that killed some 80 person and injured more than 100, the Afghan government declared 11 May as a national mourning day. (Photo by Hedayatullah Amid/EPA/EFE)