To the rank-and-file delegates to the Ninth Congress, Lin Biao must have seemed the ideal choice as a successor.1 Most important, he had been handpicked by Mao, and who better to stand beside the Chairman than one of the CCP's greatest generals at a time when China was surrounded by hostile superpowers? Indeed, the congress met at a time when war with the Soviet Union seemed a real possibility.
The previous year, Soviet-style revisionism, the cardinal sin that the Cultural Revolution was designed to extirpate in China, took an alarming new turn. In the summer of 1968, the Soviet Union invaded its satellite Czechoslovakia in order to eliminate its revisionism, the "communism with a human face" introduced by First Secretary Alexander Dubcek and his colleagues. The overthrow of the Dubcek regime had subsequently been justified by the "Brezhnev doctrine," which held that Moscow had a right to dispose of any government that betrayed Communist principles. While Beijing in the throes of Cultural Revolution was hardly sympathetic to the "Prague spring," the implications of the Brezhnev doctrine were deeply unsettling for a Chinese regime that Moscow manifestly detested. The Chinese dubbed the Soviet actions and doctrine "social imperialism."2 As Zhou Enlai later put it to a Vietcong delegation, "This has created a precedent that allows a socialist country to intervene in another socialist country's affairs."3
Simultaneously, conventional "imperialism" was a potential threat on China's southern border. Mao had launched the Cultural Revolution on the assumption that the Vietnam War would not spill over into China at a time of internal upheaval.4 Even so, in the mid-1960s he had ordered the transfer of vital industries to the far interior, the so-called Third Front,5 a massively expensive dislocation of the economy—over 200 billion yuan according to a later Chinese estimate6— and at a CC work conference in the autumn of 1965, national defense, including