 Some of these fighters used to be soldiers and officers in the Soviet Army during the Russian invasion of Afghanistan in the 1980s, and some of them had military training given by the CIA during the 1990s; hence they were experts in guerrilla warfare.The IMU fighters had little to lose and it was difficult for them to escape somewhere else.They couldn't go back to Uzbekistan, and after 2009, re-infiltration back to Afghanistan also started becoming more difficult.