Enough evidence has seeped through the Bamboo Curtain to determine some of the main issues in the new power struggle in Peking. The evidence has to be found between the lines of the Chinese newspapers, many of which are not allowed out of the country. One of the papers that reaches foreigners only when it is smuggled out, usually to Hong Kong, where eager intelligence services from more than one country are prepared to pay a handsome price for single copies, is the Liberation Army Daily.

Earlier in the year there was much talk in China bout the need to strengthen the army. The new leadership that had overthrown the "Gang of Four" expressed itself emphatically in favor of this. It could not have defeated the "Gang" without the army's support, and it was prepared to pay the price usually demanded by the military for services rendered to politicians - that is, more and better arms. But the Liberation Army Daily seemed to have some doubts about the politicians' promises.

Using phrases out of their own speeches, it insisted that the army should "not only" be strengthened, but also that its modernization should be speeded up. Party Chairman Hua Kuo-feng had recently proclaimed a new policy of sharply accelerating the country's economic development - a task that, he said, brooks no delay. Speed, he explained, was "a political rather than a purely economic question." He was saying, in effect, that the only way to give the army what it wanted was to develop the economy first, and that the military could not therefore have all it wanted.

But the Liberation Army Daily turned his formula around to bolster its own argument. "The question of speed is a very sharp political question," it said, but it concluded from this that in view of the possibility of war, China should make "earlier and better" preparations for it, in order to be "more certain" of victory. "Lagging behind means passivity and being beaten by others."

It pointed out that both the Soviet Union and the United States had been accelerating their military programs, and it implied that China must do likewise. "The situation is compelling, and time waits for no one . . . We must prepare against the eventuality of an early, major war. We must race for time against the enemy and work as quickly as possible, making one year counts as two.

The debate at which the army newspaper hinted in the summer still goes on. Last month Vice Premier Yu Chiu-li, who is in charge of economic development, made a speech that was clearly meant as a reply to the military and to those politicans who support it. "Facts show," he insisted, that the policy decisions made by Hua to speed up economic development "are entirely correct," and that they "conform to the will of the people." There are obviously still those who maintain that Hua's policy is not correct, and they are to be found in the party's highest leadership. The speed of economic development, said the People's Daily in an editorial on Yu's speech, must be increased, and "leading comrades at various levels must have a correct understanding of this point."

The issue is not only a military one. More rapid economic development requires the abandonment of Mao's policies, which sought to protect China from being contaminated by the evils of industrialization. One of the effects of industrialization already evident in China is greater discipline, higher wages, more emphasis on the role of the worker rather than the peasant - all of which are regarded by Maoist dogma as features of Soviet revisionism.

It is not just the "remnants of the Gang of Four" who are opposed to these innovations. The intensified campaign against the "remnants" in the Chinese press is conducted in a way that reveals its true target - those who refuse to abandon the policies they believe to have been bequeathed to them by Mao. They are not radicals, but Maoists, and they question the new leadership's claim to Mao's mantle. It is these "true Maoists" who appear to have made a tactical alliance with those army leaders who oppose the undue concentration on economic development that takes away the resources necessary for a more rapid military buildup.

Both the economy and the military compete for the same resources, such as steel. The steel that goes into the new factories, or into the tractors that are to be produced in huge numbers under Hua's agricultural mechanization plan, cannot be spared for the new tanks and other equipment that China's huge and backward army needs so badly. Earlier in the year Marshal Yeh Chien-ying, the minister of defense, explained that steel was "the key link." He urged the rapid development of the steel industry, as the first of a number of primary industries that, he said, would put defense "on a strong basis."

Since then, however, steel has been dropped from the priority list, on the ground that the "proportionate" development of the economy requires that prior attention be given to other industries. Before steel can have the resources it needs, China must develop the coal and electric-power industries and transportation. "There is not even one express highway in the whole country," says the People's Daily." Nor can industry be developed if agriculture lags behind. Without bread, the worker could not work, and the soldier could not fight. It is the mechanization of agriculture, says the People's Daily, that must come first - "otherwise, we will never win victories, even if we have the guns."

The guns v. butter debate in Peking explains the recent signs in the Chinese press of struggles in the top leadership, particularly the complaints of an army plot against the political leaders. It is a debate that could easily degenerate into a power struggle of the kind that repeatedly erupted in Peking during Mao's lifetime.