ONE of the hallmarks of totalitarian regimes is that they believe they have the absolute right to interfere in and direct the lives of their citizens in a way no free society would consider. But even by the standards of authoritarian governments, China's planned foray into eugenics is offensive. Not since the experiments of the fascist dictatorships of the 1930s and 1940s have governments been so open about attempting, as Xinhua (the New China News Agency) put it, ''to use legal means to avoid new births of inferior quality and heighten the standards of the whole population''. China's plan, in the form of a draft law on eugenics and health protection, has yet to be approved by the National People's Congress Standing Committee. But even to prepare such a law indicates a basic lack of respect for individual rights among Chinese officialdom. Not only is the idea offensive, it also would be ineffective. Any justification of this abuse of power on the basis of its practical social benefits would fail because of the lack of significant gains. It may be true, as Xinhua coldly explains, that China has more than 10 million disabled persons who ''could have been prevented'' by better controls. But it is questionable whether the controls now proposed would have ''prevented'' anything like that number. In millions of cases, it is unlikely that the risks were identified in advance or that the parents were aware of the dangers. Genetic problems often become apparent only after the birth of an affected child. Nor can the plan be justified on the grounds that there is no alternative. Those with curable diseases would have benefited more from better general health care and education, ante-natal and mother and child health programmes than from knife-wielding surgeons. Given the choice between waiting for a cure and producing a sick, deformed or disabled child, few women would need to be asked twice. But China's record for disguising sterilisation programmes as family planning under its one-child policy would makemany mothers suspicious of the real intentions of the official doctors sent to counsel them. Incurable diseases raise much more serious problems. Hepatitis is endemic in Asia, but not always fatal. Not every carrier will develop the disease, though one in four will develop liver cancer later in life. Although the infection rate is high, not every child born to carriers will be a victim. Often the cycle can be broken by vaccination of the newborn. Are all hepatitis carriers to be sterilised and permanently banned from marrying? Are all the mentally ill to be condemned to celibacy and sterilisation? There are other dangers. Science's understanding of genetics and heredity in disease is still in its infancy. As knowledge improves it may be possible more accurately to predict the likelihood of abnormality. But a little knowledge is also a dangerous thing. Are women whose mothers developed breast-cancer, for instance, to be sterilised because they may be genetically predisposed to the disease and could pass it on to their daughters? Advice is one thing, compulsion is another. And where does the control stop? Travellers have reported increased birth abnormalities in the vicinity of China's nuclear test site in the Lop Nor desert. Does that put everyone in the region at risk of being sterilised? And in remote areas where inbreeding has led to a higher incidence of abnormality, will whole villages which happen to share the same family name be in the same peril? The new policy will inflame critics of China's human rights. The one-child policy itself is under international attack as a human rights abuse. International groups already have been questioning aid to family planning programmes in China for fear the money is being misused on forced sterilisation. A report earlier this month of hospital officials being sentenced to death for helping women escape compulsory sterilisation was presented as an anti-corruption success. But it also demonstrated the depth of resentment against the one-child policy and its enforcement. The draft law insists that trained officials and strictly approved organisations must be involved in pre-marital health checks and sterilisation. But the fear must be that they will be in positions where power can be abused for political ends or personalgain. China can ill-afford another preventable human rights battle. Whether in the United States Congress or among international aid and family planning agencies, concern is growing over the way China treats its citizens. New displays of inhumanity are the lastthing China's image - or its people - needs.