 In August 1991, following his arrival in power, Boris Yeltsin announced that all direct assistance to Najibullah's regime would be curtailed.In January 1992, the Afghan Air Force, which had proved vital to the survival of the regime, could no longer fly any aircraft for lack of fuel.The army suffered from crippling food shortages, causing the desertion rate to rise by 60 percent between 1990 and 1991.