EARLY in April, Jiang Zemin, Secretary General of China's Communist Party, came to Tokyo on an enigmatic goodwill mission - the first senior Chinese leader to visit Japan since the democracy movement was crushed in 1989.
Jiang brought a carrot, and a stick. He offered China as an investment opportunity for Japanese business and a market for Japan's exports. But he wielded a stick as well: Japan, said Jiang, is not to send any soldiers abroad, even in a United Nations peacekeeping operation.
Why a top-rank figure who holds no office of state was entrusted with this message of the highest diplomatic importance is open to speculation. There is no doubt about its meaning or its underlying menace, which goes beyond Japan. To be sure, the shock was felt most directly in Tokyo. Japan, conscious of its economic power, and seeking a commensurate world role, is looking to the United Nations. It is now the second largest contributor to the UN's regular budget and wants a permanent seat on the Security
Council. The nation is debating assigning peacekeeping troops to the UN as a legitimate way of casting off the constitutional restraints that tie its defense forces to the homeland.
Japan is deeply involved in financing the largest, most complex peacekeeping operation the UN has ever undertaken: UNTAC, the UN Transitional Authority in Cambodia. A Japanese diplomat, Yasushi Akashi, is in charge of the whole enterprise under UN Secretary General Boutros Boutros-Ghali. It is not wrong for Japan to work at overcoming the hatred and suspicion it earned in World War II, and even at gaining influence in Southeast Asia. Beijing's message, through Jiang Zemin, was: Forget it, that region is China's backyard.
History casts a long shadow from the north on Southeast Asia. In times of imperial greatness, China was the suzerain. It had no boundaries. The emperor's power radiated in all directions as far as security required. The peoples on the periphery comported themselves to his will. It was in the century of China's decline that Britain and France moved into its southern and Russia into its northern and western zones of influence, while Japan took Korea and Taiwan.
Today, the strategic balance is altered. Mainland China is again under strong central control. Russian Siberia is no longer a threat. Soviet activity in Indochina has ended; the nearby American air and naval presence in the Philippines is going. Beijing is looking southward. It fully supports Burma's regime in stamping out sparks of democracy among the Burmese and brutalizing non-Burmese minorities. China commands the cooperation of Thailand, perhaps for the price of turning off an unpleasant communist i nsurgency in the south. But its main focus is Indochina.
THE murderous Khmer Rouge has been and remains China's instrument in Cambodia. There, in 1978, the ancient Sino-Vietnamese enmity flared up. The Vietnamese army invaded Cambodia, drove out the Khmer Rouge, and set up a compliant regime in Phnom Penh, whereupon China sent its army into northern Vietnam to "teach Hanoi a lesson." But Vietnam fought the Chinese off. Beijing responded by activating the Khmer Rouge on a large scale, armed and supplied through Thailand, and linking it with the forces of Prince
Norodom Sihanouk and Son Sann in a civil war against Phnom Penh.
In time, the Khmer Rouge accepted a peace agreement, which is guaranteed by China, the United States, Britain, France, and Russia. It is the blueprint of a new, democratic Cambodia. Yet, there is strong reason to suspect that the Khmer Rouge intends to be not a partner in a coalition but the ruler. It has recently given UNTAC limited access to its territory while showing reluctance to let the UN peacekeepers, as agreed, demobilize and disarm its forces. It has herded refugees into Cambodia from its camps
in Thailand so that if an election is held next spring, as planned, the Khmer Rouge vote will be solid. It uses terror and disorder with raids and infiltration to make peace impossible except on its terms.
Some experts believe the Khmer Rouge is now playing its own game independent of China and in cahoots with the corrupt Thai generals. In any case, its actions throw into question the success of UNTAC, democracy in Cambodia, and the chance of an independent power balance in Southeast Asia.