Soviet leader Mikhail Gorbachev in 1989 proposed a peace plan in cooperation with leader of Afghanistan, Mohammad Najibullah, for the joint cutoff of Soviet and American aid to the government and guerillas respectively, to result in a ceasefire and peace negotiations. Najibullah sought American cooperation in achieving a political solution. However the newly elected administration of George H. W. Bush rejected the plan, expecting to win the war through battle. Almost immediately after the Soviet withdrawal the mujahideen attacked the eastern city of Jalalabad in a plan instigated by Hamid Gul of Pakistan's Inter-Service Intelligence (ISI). Both the Americans and Pakistanis expected for Jalalabad to rapidly fall to the guerillas and lead to a final victorious attack in Kabul. The Afghan Army proved their capability without Soviet troops as they managed to restrain the mujahideen attack, resulting in a major defeat for the mujahideen.