Why did the Soviet Union fail to defeat the Mujahedin‪?‬

Throughout the 1980s the war in Afghanistan, which started as a civil war, developed into a “bloody Cold War battlefield” (Jalali, 2001: 85) with Soviet troops fighting alongside Afghan government troops against resistance fighters supported by Pakistan and the USA. During this almost ten years lasting war, which ended with the withdrawal of the Red Army in February 1989, the Soviet Union failed to defeat the Mujahedin primarily due to an initially false strategic alignment and severe tactical deficiencies.