A 15-month investigation by the Guardian and BBC Arabic reveals how retired US colonel James Steele, a veteran of American proxy wars in El Salvador and Nicaragua, played a key role in training and overseeing US-funded special police commandos who ran a network of torture centres in Iraq. Another special forces veteran, Colonel James Coffman, worked with Steele and reported directly to General David Petraeus, who had been sent into Iraq to organise the Iraqi security services.