Amin's short-lived leadership featured controversies from beginning to end. His government failed to solve the problem of the population revolting against the regime as the situation rapidly worsened and army desertions and defections continued. He tried to change things with friendly overtures to Pakistan and the United States, and considered a trade-off of recognizing the Durand Line border in exchange of Pakistan to halt support to anti-regime guerillas. Many Afghans held Amin responsible for the regime's harshest measures, such as ordering thousands of executions. Thousands of people disappeared without trace during his time in office. The Soviet Union under Leonid Brezhnev was dissatisfied with and mistrusted Amin; they intervened in Afghanistan, invoking the 1978 Twenty-Year Treaty of Friendship between Afghanistan and the Soviet Union. Soviet operatives assassinated Amin at the Tajbeg Palace on 27 December 1979 as part of Operation Storm-333, kickstarting the 10-year Soviet–Afghan War; he had ruled for slightly longer than three months.