TAIWAN HAS DECREED an end to the martial law that the ruling Nationalist Party imposed 38 years ago when the communists chased its forces off the Chinese mainland. It is not instant democracy. The powers the military has administered are not being abolished but are being put into civilian hands. The system is set up to ensure that most of those hands are the Kuomintang's; four-fifths of the seats in the legislature, for instance, are held by people elected in mainland China districts in 1947 or by their party-appointed successors. Still, civilians are henceforth to be tried in civilian courts, and the way has been opened wider to a system of legalized political parties. Psychologically and politically, it is an important step forward.

President Chiang Ching-kuo's new gesture demonstrates to Americans and others that the Republic of China is staying ahead of the pressures that have convulsed other authoritarian regimes. It also reflects real changes on the island itself. Socially and economically, Taiwan has modernized impressively in the past four decades, rendering authoritarian rule increasingly anomalous and creating a popular demand for a more relaxed and dignified system. Wary as it is, the Nationalist Party, which speaks principally for Chinese who came from the mainland, has seen liberalization as a way to make itself more popular to the majority (80-plus percent) of native Taiwanese. It offers the prosperity and stability it has already delivered, plus the promise of political relaxation, not just as values in themselves but also as substitutes for the self-determination that many Taiwanese have on their minds.

In moving toward a political opening, nonetheless, the government on Taiwan deserves respect. Its pace may be slow and its relaxation of its grip tentative. But it is edging into uncharted terrain where the liberalization it now is exploring could be used to challenge its political dominance. The democratic cause is advancing on a global front, and this is President Chiang's contribution to it.