What motivates Russia's black widow suicide bombers?
Women bombers have often suffered trauma in their past before being exposed to jihadist ideas
The rash of deadly bombings that have struck Russia in recent days have understandably provoked safety fears ahead of the Sochi Olympics, but outsiders might also be wondering why so many of those committing the country's worst acts of terrorism are women.
Female suicide bombers are hardly an unknown phenomenon in conflicts ranging from Israel-Palestine to Sri Lanka, but the role of the "Black Widows" as they've been dubbed in the press, seems particularly prominent and high-profile in the long-running insurgency in the North Caucasus.
A female bomber, Naida Asiyalova, was responsible for a bus bombing in Volgograd in October that killed five people.
Female bombers are also believed to have carried out the attack on the Moscow Metro that left 38 dead in 2010 and took part in Russia's two worst modern terrorist attacks: the 2002 Nord-Ost theatre siege and the 2004 Beslan school attack.
They only speak about routine problems … they fear public humiliation
The first Black Widow attack was in 2000, when Khava Baraeva drove a truck filled with explosives into a building housing Russian special forces in Chechnya. In August, journalist Anna Nemtsova wrote on the Daily Beast that "In the last 12 years, 46 women have turned themselves into suicide bombs in Russia, committing 26 terrorist attacks (some attacks involved multiple women). Most of the bombers were from Chechnya and Dagestan."
Most studies of Chechen female suicide bombers have found that they tend to be women who have experienced serious personal trauma and are then exposed to recruitment from jihadist military groups. As the term Black Widow would suggest, many have lost close family members over the last two decades of violence since war first broke out in Chechnya.