Najibullah was appointed to the PDPA Secretariat in November 1985. During Karmal's March 1986 visit to the Soviet Union, the Soviets tried to persuade Karmal that he was too ill to govern, and that he should resign. This backfired, as a Soviet doctor attending to Karmal told him he was in good health. Karmal asked to return home to Kabul, and said that he understood and would listen to the Soviet recommendations. Before leaving, Karmal promised he would step down as PDPA General Secretary. The Soviets did not trust him and sent Vladimir Kryuchkov, the head of intelligence (FCD) in the KGB, into Afghanistan. At a meeting in Kabul, Karmal confessed his undying love for the Soviet Union, comparing his ardor to his Muslim faith. Kryuchkov, concluding that he could not persuade Karmal to resign, left the meeting. After Kryuchkov left the room, the Afghan defence minister and the state security minister visited Karmal's office, telling him that he had to resign from one of his posts. Understanding that his Soviet support had been eliminated, Karmal resigned from the office of the General Secretary at the 18th PDPA Central Committee plenum. He was succeeded in his post by Najibullah.