Amin trusted the Soviet Union until the very end, despite the deterioration of official relations, and was unaware that the tide in Moscow had turned against him since he ordered Taraki's death. When the Afghan intelligence service handed Amin a report that the Soviet Union would invade the country and topple him, Amin claimed that the report was a product of imperialism. His view can be explained by the fact that the Soviet Union, after several months, finally gave in to Amin's demands and sent troops into Afghanistan to secure the PDPA government. Contrary to common Western belief, Amin was informed of the Soviet decision to send troops into Afghanistan. General Tukharinov, commander of the 40th Army, met with Afghan Major General Babadzhan to talk about Soviet troop movements before the Soviet army's intervention. On 25 December, Dmitry Ustinov issued a formal order, stating that "he state frontier of the Democratic Republic of Afghanistan is to be crossed on the ground and in the air by forces of the 40th Army and the Air Force at 1500 hrs on 25 December". This was the formal beginning of the Soviet intervention in Afghanistan.