Ravaged by 40 years of war, the Afghan capital Kabul is one of the most dangerous cities in the world. Every day, people there are victims of murders, kidnappings and muggings. Recently, the murder of a student – killed for refusing to give up his laptop – became a symbol of residents' exasperation. As a result, the police have reinforced their presence in the capital, but the notoriously corrupt and under-staffed institution is struggling to ensure the safety of Kabul's citizens. Our correspondents report.