THE quicker the Americans find their way clear to doing away with the annual renewal of China's MFN status the better. And that is not stating the case for China - that is stating the case for the United States and its future prestige in Asia. It now seems clear the Americans are bending over backwards to ensure renewal of MFN. Secretary of State Warren Christopher's remarks to a Congressional hearing on Thursday that China was making advances in some areas of human rights sounded faintly ridiculous. This is not because China has or has not made any human rights advances, but because his claim followed so closely on his recent trip to Beijing. Reports of his reception on that trip and the progress made during the visit were almost entirely negative. Yet a day later he was claiming limited progress and President Clinton was saying the trip had been a success. A few days after that the President went a step further, saying that he thought the US and China could work out their differences on trade andhuman rights. And then it was Mr Christopher's turn to put his latest positive ''spin'' on US ''successes'' in talks with China. The Secretary of State is now claiming the US could impose some restraints but the issue remains very embarrassing for ''the world's remaining super-power''. It makes US policy towards China look a shambles and diminishes US prestige in the whole Asian region. Worse still, the whole shambles is entirely the fault of the Clinton Administration. It got itself into the current mess with its executive order on MFN, now it has to get itself out.